Color Atlas of Hematology (2004).pdf

Theml, Color Atlas of Hematology © 2004 Thieme 

All rights reserved. Usage subject to terms and conditions of license. 

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All rights reserved. Usage subject to terms and conditions of license.

Color Atlas of Hematology 

Practical Microscopic and Clinical Diagnosis 

Harald Theml, M.D. 

Professor, Private Practice 

Hematology/Oncology 

Munich, Germany 

Heinz Diem, M.D. 

Klinikum Grosshadern 

Institute of Clinical Chemistry 


Torsten Haferlach, M.D. 

Professor, Klinikum Grosshadern 

Laboratory for Leukemia Diagnostics 


2nd revised edition 

262 color illustrations 

32 tables 

Thieme 

Stuttgart · New York 



iii

iv 

Library of Congress Cataloging-in-Publication 

Data is available from the publisher 

This book is an authorized revised 

translation of the 5th German edition 

published and copyrighted 2002 by 

Thieme Verlag, Stuttgart, Germany. 

Title of the German edition: 

Taschenatlas der Hämatologie 

Translator: Ursula Peter-Czichi PhD, 

Atlanta, GA, USA 

1st German edition 1983 

2nd German edition 1986 

3rd German edition 1991 

4th German edition 1998 

5th German edition 2002 

1st English edition 1985 

1st French edition 1985 

2nd French edition 2000 

1st Indonesion edition 1989 

1st Italian edition 1984 

1st Japanese edition 1997 

2004 Georg Thieme Verlag 

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Germany 

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Thieme New York, 333 Seventh Avenue, 

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Druckhaus Götz GmbH, Ludwigsburg 

ISBN 3-13-673102-6 (GTV) 

ISBN 1-58890-193-9 (TNY) 1 2 3 4 5 

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development. Research and clinical experience 

are continually expanding our 

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readers may rest assured that the 

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every effort to ensure that such references 

are in accordance with the state of knowledge 

at the time of production of the 

book. 

Nevertheless, this does not involve, imply, 

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Preface 

Our Current Edition 

Although this is the second English edition of our hematology atlas, this 

edition is completely new. As an immediate sign of this change, there are 

now three authors. The completely updated visual presentation uses digital 

images, and the content is organized according to the most up-to-date 

morphological classification criteria. 

In this new edition, our newly formed team of authors from Munich 

(the “Munich Group”) has successfully shared their knowledge with you. 

Heinz Diem and Torsten Haferlach are nationally recognized as lecturers 

of the diagnostics curriculum of the German Association for Hematology 

and Oncology. 

Goals 

Most physicians are fundamentally “visually oriented.” Apart from immediate 

patient care, the microscopic analysis of blood plays to this preference. 

This explains the delight and level of involvement on the part of 

practitioners in the pursuit of morphological analyses. 

Specialization notwithstanding, the hematologist wants to preserve 

the opportunity to perform groundbreaking diagnostics in hematology for 

the general practitioner, surgeon, pediatrician, the MTA technician, and all 

medical support personnel. New colleagues must also be won to the 

cause. Utmost attention to the analysis of hematological changes is essential 

for a timely diagnosis. 

Even before bone marrow cytology, cytochemistry, or immunocytochemistry, 

information based on the analysis of blood is of immediate relevance 

in the doctor’s office. It is central to the diagnosis of the diseases of 

the blood cell systems themselves, which make their presence known 

through changes in blood components. 

The exhaustive quantitative and qualitative use of hematological diagnostics 

is crucial. Discussions with colleagues from all specialties and 

teaching experience with advanced medical students confirm its importance. 

In cases where a diagnosis remains elusive, the awareness of the 

next diagnostic step becomes relevant. Then, further investigation 

through bone marrow, lymph node, or organ tissue cytology can yield firm 

results. This pocket atlas offers the basic knowledge for the use of these 

techniques as well. 



v

vi 

Preface 

Organization 

Reflecting our goals, the inductive organization proceeds from simple to 

specialized diagnostics. By design, we subordinated the description of the 

bone marrow cytology to the diagnostic blood analysis (CBC). However, 

we have responded to feedback from readers of the previous editions and 

have included the principles of bone marrow diagnostics and nonambiguous 

clinical bone marrow findings so that frequent and relevant 

diagnoses can be quickly made, understood, or replicated. 

The nosology and differential diagnosis of hematological diseases are 

presented to you in a tabular form. We wanted to offer you a pocketbook 

for everyday work, not a reference book. Therefore, morphological curiosities, 

or anomalies, are absent in favor of a practical approach to morphology. 

The cellular components of organ biopsies and exudates are 

briefly discussed, mostly as a reminder of the importance of these tests. 

The images are consistently photographed as they normally appear in 

microscopy (magnification 100 or 63 with oil immersion lens, occasionally 

master-detail magnification objective 10 or 20). Even though 

surprising perspectives sometimes result from viewing cells at a higher 

magnification, the downside is that this by no means facilitates the recognition 

of cells using your own microscope. 

Instructions for the Use of this Atlas 

The organization of this atlas supports a systematic approach to the study 

of hematology (see Table of Contents). The index offers ways to answer 

detailed questions and access the hematological terminology with references 

to the main description and further citations. 

The best way to become familiar with your pocket atlas is to first have a 

cursory look through its entire content. The images are accompanied by 

short legends. On the pages opposite the images you will find corresponding 

short descriptive texts and tables. This text portion describes cell phenomena 

and discusses in more detail further diagnostic steps as well as 

the diagnostic approach to disease manifestations. 

Acknowledgments 

Twenty years ago, Professor Herbert Begemann dedicated the foreword to 

the first edition of this hematology atlas. He acknowledged that—beyond 

cell morphology—this atlas aims at the clinical picture of patients. We are 

grateful for being able to continue this tradition, and for the impulses from 

our teachers and companions that make this possible. 

We thank our colleagues: J. Rastetter, W. Kaboth, K. Lennert, H. Löffler, 

H. Heimpel, P.M. Reisert, H. Brücher, W. Enne, T. Binder, H.D. Schick, W. 

Hiddemann, D. Seidel. 

Munich, January 2004 Harald Theml, Heinz Diem, Torsten Haferlach 



Contents 

vii 

Physiology and Pathophysiology of Blood Cells: 

Methods and Test Procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 

Introduction to the Physiology and Pathophysiology of the 

Hematopoietic System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Cell Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 

Principles of Regulation and Dysregulation in the Blood Cell 

Series and their Diagnostic Implications . . . . . . . . . . . . . . . . . . . . . . . . 7 

Procedures, Assays, and Normal Values . . . . . . . . . . . . . . . . . . . . . . . 9 

Taking Blood Samples . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 

Erythrocyte Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Hemoglobin and Hematocrit Assay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Calculation of Erythrocyte Parameters . . . . . . . . . . . . . . . . . . . . . . . . . . 10 

Red Cell Distribution Width (RDW) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Reticulocyte Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 

Leukocyte Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 

Thrombocyte Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

Quantitative Normal Values and Distribution of Cellular Blood 

Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 

The Blood Smear and Its Interpretation (Differential Blood Count, 

DBC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 

Significance of the Automated Blood Count . . . . . . . . . . . . . . . . . . . . . 19 

Bone Marrow Biopsy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 

Lymph Node Biopsy and Tumor Biopsy . . . . . . . . . . . . . . . . . . . . . . . . . 23 

Step-by-Step Diagnostic Sequence . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 

Normal Cells of the Blood and Hematopoietic Organs . 29 

The Individual Cells of Hematopoiesis . . . . . . . . . . . . . . . . . . . . . . . . 30 

Immature Red Cell Precursors: Proerythroblasts and Basophilic 

Erythroblasts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 

Mature Red Blood Precursor Cells: Polychromatic and Orthochromatic 

Erythroblasts (Normoblasts) and Reticulocytes . . . . . . . 32 

Immature White Cell Precursors: Myeloblasts and Promyelocytes 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 



viii 

Contents 

Partly Mature White Cell Precursors: Myelocytes and Metamyelocytes 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 

Mature Neutrophils: Band Cells and Segmented Neutrophils . . . . . 38 

Cell Degradation, Special Granulations, and Nuclear Appendages 

in Neutrophilic Granulocytes and Nuclear Anomalies . . . . . . . . . . . . 40 

Eosinophilic Granulocytes (Eosinophils) . . . . . . . . . . . . . . . . . . . . . . . . 44 

Basophilic Granulocytes (Basophils) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 

Monocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46 

Lymphocytes (and Plasma Cells) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 

Megakaryocytes and Thrombocytes . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 

Bone Marrow: Cell Composition and Principles of Analysis . . . . 52 

Bone Marrow: Medullary Stroma Cells . . . . . . . . . . . . . . . . . . . . . . . . . 58 

Abnormalities of the White Cell Series . . . . . . . . . . . . . . . . . . 61 

Predominance of Mononuclear Round to Oval Cells . . . . . . . . . . . 63 

Reactive Lymphocytosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66 

Examples of Extreme Lymphocytic Stimulation: Infectious 

Mononucleosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 

Diseases of the Lymphatic System (Non-Hodgkin Lymphomas) . . . 70 

Differentiation of the Lymphatic Cells and Cell Surface Marker 

Expression in Non-Hodgkin Lymphoma Cells . . . . . . . . . . . . . . . . . 72 

Chronic Lymphocytic Leukemia (CLL) and Related Diseases . . . . 74 

Lymphoplasmacytic Lymphoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 

Facultative Leukemic Lymphomas (e.g., Mantle Cell Lymphoma 

and Follicular Lymphoma) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 78 

Lymphoma, Usually with Splenomegaly (e.g., Hairy Cell Leukemia 

and Splenic Lymphoma with Villous Lymphocytes) . . . . . . . 80 

Monoclonal Gammopathy (Hypergammaglobulinemia), Multiple 

Myeloma*, Plasma Cell Myeloma, Plasmacytoma . . . . . . . . . 82 

Variability of Plasmacytoma Morphology . . . . . . . . . . . . . . . . . . . . . 84 

Relative Lymphocytosis Associated with Granulocytopenia 

(Neutropenia) and Agranulocytosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 

Classification of Neutropenias and Agranulocytoses . . . . . . . . . . . 86 

Monocytosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88 

Acute Leukemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90 

Morphological and Cytochemical Cell Identification . . . . . . . . . . . 91 

Acute Myeloid Leukemias (AML) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95 

Acute Erythroleukemia (FAB Classification Type M6) . . . . . . . . . . 100 

Acute Megakaryoblastic Leukemia 

(FAB Classification Type M7) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 

AML with Dysplasia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 

Hypoplastic AML . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 102 



Contents 

Acute Lymphoblastic Leukemia (ALL) . . . . . . . . . . . . . . . . . . . . . . . . 104 

Myelodysplasia (MDS) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 106 

Prevalence of Polynuclear (Segmented) Cells . . . . . . . . . . . . . . . . . 110 

Neutrophilia without Left Shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 110 

Reactive Left Shift . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112 

Chronic Myeloid Leukemia and Myeloproliferative Syndrome 

(Chronic Myeloproliferative Disorders, CMPD) . . . . . . . . . . . . . . . . . . 114 

Steps in the Diagnosis of Chronic Myeloid Leukemia . . . . . . . . . . 116 

Blast Crisis in Chronic Myeloid Leukemia . . . . . . . . . . . . . . . . . . . . . 120 

Osteomyelosclerosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122 

Elevated Eosinophil and Basophil Counts . . . . . . . . . . . . . . . . . . . . . . . 124 

Erythrocyte and Thrombocyte Abnormalities . . . . . . . . . . . 127 

Clinically Relevant Classification Principle for Anemias: Mean 

Erythrocyte Hemoglobin Content (MCH) . . . . . . . . . . . . . . . . . . . . . . . 128 

Hypochromic Anemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

Iron Deficiency Anemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128 

Hypochromic Infectious or Toxic Anemia (Secondary Anemia) . . . 134 

Bone Marrow Cytology in the Diagnosis of Hypochromic Anemias 

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 136 

Hypochromic Sideroachrestic Anemias (Sometimes Normochromic 

or Hyperchromic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137 

Hypochromic Anemia with Hemolysis . . . . . . . . . . . . . . . . . . . . . . . . . 138 

Thalassemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 138 

Normochromic Anemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 

Normochromic Hemolytic Anemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . 140 

Hemolytic Anemias with Erythrocyte Anomalies . . . . . . . . . . . . . . . . 144 

Normochromic Renal Anemia (Sometimes Hypochromic or 

Hyperchromic) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

Bone Marrow Aplasia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 146 

Pure Red Cell Aplasia (PRCA, Erythroblastopenia) . . . . . . . . . . . . . 146 

Aplasias of All Bone Marrow Series (Panmyelopathy, Panmyelophthisis, 

Aplastic Anemia) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148 

Bone Marrow Carcinosis and Other Space-Occupying Processes . . 150 

Hyperchromic Anemias . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152 

Erythrocyte Inclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 156 

Hematological Diagnosis of Malaria . . . . . . . . . . . . . . . . . . . . . . . . . . . . 158 



ix

x 

Contents 

Polycythemia Vera (Erythremic Polycythemia) 

and Erythrocytosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 162 

Thrombocyte Abnormalities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

Thrombocytopenia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

Thrombocytopenias Due to Increased Demand 

(High Turnover) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 164 

Thrombocytopenias Due to Reduced Cell Production . . . . . . . . . . 168 

Thrombocytosis (Including Essential Thrombocythemia) . . . . . . . . 170 

Essential Thrombocythemia . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 170 

Cytology of Organ Biopsies and Exudates . . . . . . . . . . . . . . . 173 

Lymph Node Cytology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 174 

Reactive Lymph Node Hyperplasia and Lymphogranulomatosis 

(Hodgkin Disease) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 176 

Sarcoidosis and Tuberculosis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 180 

Non-Hodgkin Lymphoma . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 

Metastases of Solid Tumors in Lymph Nodes or Subcutaneous 

Tissue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 182 

Branchial Cysts and Bronchoalveolar Lavage . . . . . . . . . . . . . . . . . . 184 

Branchial Cysts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 

Cytology of the Respiratory System, Especially Bronchoalveolar 

Lavage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 184 

Cytology of Pleural Effusions and Ascites . . . . . . . . . . . . . . . . . . . . . 186 

Cytology of Cerebrospinal Fluid . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 188 

References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 190 

Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191 



Physiology and Pathophysiology of 

Blood Cells: Methods and Test 

Procedures 



2 

Physiology and Pathophysiology of Blood Cells 

Introduction to the Physiology and 

Pathophysiology of the Hematopoietic 

System 

The reason why quantitative 

and qualitative diagnosis 

based on the cellular 

components of the blood is 

so important is that blood 

cells are easily accessible 

indicators of disturbances 

in their organs of origin or 

degradation—which are 

much less easily accessible. 

Thus, disturbances in the 

erythrocyte, granulocyte, 

and thrombocyte series 

allow important conclusions 

to be drawn about 

bone marrow function, just 

as disturbances of the lymphatic 

cells indicate reactions 

or disease states of 

the specialized lymphopoietic 

organs (basically, 

the lymph nodes, spleen, 

and the diffuse lymphatic 

intestinal organ). 

Cell Systems 

All blood cells derive from a 

common stem cell. Under 

the influences of local and 

humoral factors, stem cells 

differentiate into different 

Fig. 1 Model of cell lineages 

in hematopoiesis 

NK cells 

NK cells 

Pluripotent 

lymphatic 

stem cells 

T-lymphopoiesis 

T-lymphoblasts 

T-lymphocytes 



Pluripotent hemato- 

B-lymphopoiesis 

B-lymphoblasts 

B-lymphocytes 

Plasma cells

Omnipotent 

stem cells 

poietic stem cells 

Basophils 

Eosinophils 

Basophilic Eosinophilic 

promyelocytes promyelocytes 

Basophilic 

segmented 

granulocytes 

Eosinophilic 

segmented 

granulocytes 

Introduction to the Physiology and Pathophysiology 

cell lines (Fig. 1). Erythropoiesis and thrombopoiesis proceed independently 

once the stem cell stage has been passed, whereas monocytopoiesis 

and granulocytopoiesis are quite closely “related.” Lymphocytopoiesis 

is the most independent among the remaining cell series. Granulocytes, 

monocytes, and lymphocytes are collectively called leukocytes (white 

blood cells), a term that has been retained since the days before staining 

Monopoiesis 

Monoblasts 

Promonocytes 

Monocytes 

Macrophages 

Granulopoiesis 

monopoiesis 

Pluripotent myeloid 

stem cells 


Myeloblasts 

Promyelocytes 

Myelocytes 

Metamyelocytes 

Cells with band nuclei 

Neutrophilic 

granulocytes 

with segmented 

nuclei 

Thrombopoiesis 

Megakaryoblasts 

Megakaryocytes 

Thrombocytes 



Erythropoiesis 

Proerythroblasts 

Erythroblasts 

Erythrocytes 

3

4 

a 

b 


methods were available, when the only distinction that could be made 

was between erythrocytes (red blood cells) and the rest. 

All these cells are eukaryotic, that is, they are made up of a nucleus, 

sometimes with visible nucleoli, surrounded by cytoplasm, which may include 

various kinds of organelles, granulations, and vacuoles. 

Despite the common origin of all the cells, ordinary light microscopy 

reveals fundamental and characteristic differences in the nuclear chromatin 

structure in the different cell series and their various stages of 

maturation (Fig. 2). 

The developing cells in the granulocyte series (myeloblasts and promyelocytes), 

for example, show a delicate, fine “net-like” (reticular) structure. 

Careful microscopic examination (using fine focus adjustment to 

view different depth levels) reveals a detailed nuclear structure that resembles 

fine or coarse gravel (Fig. 2 a). With progressive stages of nuclear 

maturation in this series (myelocytes, metamyelocytes, and band or staff 

cells), the chromatin condenses into bands or streaks, giving the nucleus— 

which at the same time is adopting a characteristic curved shape—a 

spotted and striped pattern (Fig. 2 b). 

Lymphocytes, on the other hand—particularly in their circulating 

forms—always have large, solid-looking nuclei. Like cross-sections 

through geological slate, homogeneous, dense chromatin bands alternate 

with lighter interruptions and fissures (Fig. 2 c). 

Each of these cell series contains precursors that can divide (blast precursors) 

and mature or almost mature forms that can no longer divide; the 

morphological differences between these correspond not to steps in mito- 

Vacuoles Nucleus (with 

delicate reticular 

chromatin structure) 

Lobed nucleus with 

banded chromatin 

structure 

Cytoplasm 

Nucleolus 

Cytoplasmic granules 

c 

Coarse chromatin 

structure 

Fig. 2 Principles of 

cell structure with examples 

of different 

nuclear chromatin 

structure. a Cell of the 

myeloblast to promyelocyte 

type. b Cell 

of the myelocyte to 

staff or band cell type. 

c Cell of the lymphocyte 

type with 

coarsely structured 

chromatin 




sis, but result from continuous “maturation processes” of the cell nucleus 

and cytoplasm. Once this is understood, it becomes easier not to be too 

rigid about morphological distinctions between certain cell stages. The 

blastic precursors usually reside in the hematopoietic organs (bone marrow 

and lymph nodes). Since, however, a strict blood–bone marrow barrier 

does not exist (blasts are kept out of the bloodstream essentially only 

by their limited plasticity, i.e., their inability to cross the diffusion barrier 

into the bloodstream), it is in principle possible for any cell type to be 

found in peripheral blood, and when cell production is increased, the 

statistical frequency with which they cross into the bloodstream will naturally 

rise as well. Conventionally, cells are sorted left to right from immature 

to mature, so an increased level of immature cells in the bloodstream 

causes a “left shift” in the composition of a cell series—although it 

must be said that only in the precursor stages of granulopoiesis are the cell 

morphologies sufficiently distinct for this left shift to show up clearly. 

The distribution of white blood cells outside their places of origin cannot 

be inferred simply from a drop of capillary blood. This is because the 

majority of white cells remain out of circulation, “marginated” in the 

epithelial lining of vessel walls or in extravascular spaces, from where 

they may be quickly recruited back to the bloodstream. This phenomenon 

explains why white cell counts can vary rapidly without or before any 

change has taken place in the rate of their production. 

Cell functions. A brief indication of the functions of the various cell groups 

follows (see Table 1). 

Neutrophil granulocytes with segmented nuclei serve mostly to 

defend against bacteria. Predominantly outside the vascular system, in “inflamed” 

tissue, they phagocytose and lyse bacteria. The blood merely 

transports the granulocytes to their site of action. 

The function of eosinophilic granulocytes is defense against parasites; 

they have a direct cytotoxic action on parasites and their eggs and larvae. 

They also play a role in the down-regulation of anaphylactic shock reactions 

and autoimmune responses, thus controlling the influence of basophilic 

cells. 

The main function of basophilic granulocytes and their tissue-bound 

equivalents (tissue mast cells) is to regulate circulation through the release 

of substances such as histamine, serotonin, and heparin. These tissue 

hormones increase vascular permeability at the site of various local antigen 

activity and thus regulate the influx of the other inflammatory cells. 

The main function of monocytes is the defense against bacteria, fungi, 

viruses, and foreign bodies. Defensive activities take place mostly outside 

the vessels by phagocytosis. Monocytes also break down endogenous cells 

(e.g., erythrocytes) at the end of their life cycles, and they are assumed to 

perform a similar function in defense against tumors. Outside the bloodstream, 

monocytes develop into histiocytes; macrophages in the 



5

6 


endothelium of the body cavities; epithelioid cells; foreign body macrophages 

(including Langhans’ giant cells); and many other cells. 

Lymphocytes are divided into two major basic groups according to 

function. 

Thymus-dependent T-lymphocytes, which make up about 70% of 

lymphocytes, provide local defense against antigens from organic and inorganic 

foreign bodies in the form of delayed-type hypersensitivity, as classically 

exemplified by the tuberculin reaction. T-lymphocytes are divided 

into helper cells and suppressor cells. The small group of NK (natural 

killer) cells, which have a direct cytotoxic function, is closely related to the 

T-cell group. 

The other group is the bone-marrow-dependent B-lymphocytes or Bcells, 

which make up about 20% of lymphocytes. Through their development 

into immunoglobulin-secreting plasma cells, B-lymphocytes are responsible 

for the entire humoral side of defense against viruses, bacteria, 

and allergens. 

Table 1 Cells in a normal peripheral blood smear and their physiological roles 

Cell type Function Count 

(% of leukocytes) 

Neutrophilic band 

granulocytes (band 

neutrophil) 

Neutrophilic segmented 

granulocyte (segmented 

neutrophil) 

Lymphocytes 

(B- and T-lymphocytes, 

morphologically indistinguishable) 

Precursors of segmented cells 

that provide antibacterial 

immune response 

Phagocytosis of bacteria; 

migrate into tissue for this purpose 

B-lymphocytes (20% of ⎫ 

lymphocytes) mature and ⎪ 

form plasma cells antibody 

⎪ 

⎪ 

production. 

⎬ 

T-lymphocytes (70%): cyto- ⎪ 

toxic defense against viruses, ⎪ 

foreign antigens, and tumors. ⎭ 

Monocytes Phagocytosis of bacteria, protozoa, 

fungi, foreign bodies. 

Transformation in target tissue 

Eosinophilic granulocytes Immune defense against parasites, 

immune regulation 

Basophilic granulocytes Regulation of the response to 

local inflammatory processes 

0–4% 

50–70% 

20–50% 

2–8% 

1–4% 

0–1% 




Erythrocytes are the oxygen carriers for all oxygen-dependent metabolic 

reactions in the organism. They are the only blood cells without nuclei, 

since this allows them to bind and exchange the greatest number of 

O2 molecules. Their physiological biconcave disk shape with a thick rim 

provides optimal plasticity. 

Thrombocytes form the aggregates that, along with humoral coagulation 

factors, close up vascular lesions. During the aggregation process, in 

addition to the mechanical function, thrombocytic granules also release 

factors that promote coagulation. 

Thrombocytes develop from polyploid megakaryocytes in the bone 

marrow. They are the enucleated, fragmented cytoplasmic portions of 

these progenitor cells. 

Principles of Regulation and Dysregulation in the 

Blood Cell Series and their Diagnostic Implications 

Quantitative and qualitative equilibrium between all blood cells is maintained 

under normal conditions through regulation by humoral factors, 

which ensure a balance between cell production (mostly in the bone marrow) 

and cell degradation (mostly in the spleen, liver, bone marrow, and 

the diffuse reticular tissue). 

Compensatory increases in cell production are induced by cell loss or increased 

cell demand. This compensatory process can lead to qualitative 

changes in the composition of the blood, e.g., the occurrence of nucleated 

red cell precursors compensating for blood loss or increased oxygen requirement, 

or following deficiency of certain metabolites (in the restitution 

phase, e.g., during iron or vitamin supplementation). Similarly, 

during acute immune reactions, which lead to an increased demand for 

cells, immature leukocyte forms may appear (“left shift”). 

Increased cell counts in one series can lead to suppression of cell production 

in another series. The classic example is the suppression of erythrocyte 

production (the pathomechanical details of which are incompletely 

understood) during infectious/toxic reactions, which affect the white cells 

(“infectious anemia”). 

Metabolite deficiency as a pathogenic stimulus affects the erythrocyte series 

first and most frequently. Although other cell series are also affected, 

this series, with its high turnover, is the one most vulnerable to metabolite 

deficiencies. Iron deficiency, for example, rapidly leads to reduced 

hemoglobin in the erythrocytes, while vitamin B12 and/or folic acid deficiency 

will result in complex disturbances in cell formation. Eventually, 

these disturbances will start to show effects in the other cell series as well. 



7

8 


Toxic influences on cell production usually affect all cell series. The effects 

of toxic chemicals (including alcohol), irradiation, chronic infections, or 

tumor load, for example, usually lead to a greater or lesser degree of suppression 

in all the blood cell series, lymphocytes and thrombocytes being 

the most resistant. The most extreme result of toxic effects is panmyelophthisis 

(the synonym “aplastic anemia” ignores the fact that the leukocyte 

and thrombocyte series are usually also affected). 

Autoimmune and allergic processes may selectively affect a single cell series. 

Results of this include “allergic” agranulocytosis, immunohemolytic 

anemia, and thrombocytopenia triggered by either infection or medication. 

Autoimmune suppression of the pluripotent stem cells can also 

occur, causing panmyelophthisis. 

Malignant dedifferentiation can basically occur in cells of any lineage at 

any stage where the cells are able to divide, causing chronic or acute clinical 

manifestations. These deviations from normal differentiation occur most 

frequently in the white cell series, causing “leukemias.” Recent data indicate 

that in fact in these cases the remaining cell series also become distorted, 

perhaps via generalized atypical stem cell formation. Erythroblastosis, 

polycythemia, and essential thrombocythemia are examples showing 

that malignant processes can also manifest themselves primarily in 

the erythrocyte or thrombocyte series. 

Malignant “transformations” always affect blood cell precursors that 

are still capable of dividing, and the result is an accumulation of identical, 

constantly self-reproducing blastocytes. These are not necessarily always 

observed in the bloodstream, but can remain in the bone marrow. That is 

why, in “leukemia,” it is often not the number of cells, but the increasing 

lack of normal cells that is the indicative hematological finding. 

All disturbances of bone marrow function are accompanied by quantitative 

and/or qualitative changes in the composition of blood cells or 

blood proteins. Consequently, in most disorders, careful analysis of 

changes in the blood together with clinical findings and other laboratory 

data produces the same information as bone marrow cytology. The relationship 

between the production site (bone marrow) and the destination 

(the blood) is rarely so fundamentally disturbed that hematological analysis 

and humoral parameters will not suffice for a diagnosis. This is virtually 

always true for hypoplastic–anaplastic processes in one or all cell series 

with resulting cytopenia but without hematological signs of malignant 

cell proliferation. 



Procedures, Assays, and Normal Values 

Taking Blood Samples 


Since cell counts are affected by the state of the blood circulation, the 

conditions under which samples are taken should be the same so far as 

possible if comparable values are desired. 

This means that blood should always be drawn at about the same time of 

day and after at least eight hours of fasting, since both circadian rhythm 

and nutritional status can affect the findings. If strictly comparable values 

are required, there should also be half an hour of bed rest before the 

sample is drawn, but this is only practicable in a hospital setting. In other 

settings (i.e., outpatient clinics), bringing portable instruments to the relaxed, 

seated patient works well. 

A sample of capillary blood may be taken when there are no further 

tests that would require venous access for a larger sample volume. A wellperfused 

fingertip or an earlobe is ideal; in newborns or young infants, the 

heel is also a good site. If the circulation is poor, the blood flow can be increased 

by warming the extremity by immersing it in warm water. 

Without pressure, the puncture area is swabbed several times with 70% 

alcohol, and the skin is then punctured firmly but gently with a sterile disposable 

lancet. The first droplet of blood is discarded because it may be 

contaminated, and the ensuing blood is drawn into the pipette (see 

below). Care should be taken not to exert pressure on the tissue from 

which the blood is being drawn, because this too can change the cell composition 

of the sample. 

Obviously, if a venous blood sample is to be taken for the purposes of 

other tests, or if an intravenous injection is going to be performed, the 

blood sample for hematological analysis can be taken from the same site. 

To do this, the blood is allowed to flow via an intravenous needle into a 

specially prepared (commercially available) EDTA-treated tube. The tube 

is filled to the 1-ml mark and then carefully shaken several times. The very 

small amount of EDTA in the tube prevents the blood from clotting, but 

can itself be safely ignored in the quantitative analysis. 



9

10 


Erythrocyte Count 

Up to 20 years ago, blood cells were counted “by hand” in an optical counting 

chamber. This method has now been almost completely abandoned in 

favor of automated counters that determine the number of erythrocytes 

by measuring the impedance or light dispersion of EDTA blood (1 ml), or 

heparinized capillary blood. Due to differences in the hematocrit, the 

value from a sample taken after (at least 15 minutes’) standing or physical 

activity will be 5–10% higher than the value from a sample taken after 15 

minutes’ bed rest. 

Hemoglobin and Hematocrit Assay 

Hemoglobin is oxidized to cyanmethemoglobin by the addition of cyanide, 

and the cyanmethemoglobin is then determined spectrophotometrically 

by the automated counter. The hematocrit describes the ratio 

of the volume of erythrocytes to the total blood volume (the SI unit is 

without dimension, e.g., 0.4). 

The EDTA blood is centrifuged in a disposable capillary tube for 10 

minutes using a high-speed microhematocrit centrifuge (reference 

method). The automated hematology counter determines the mean corpuscular 

or cell volume (MCV, measured in femtoliters, fl) and the number 

of erythrocytes. It calculates the hematocrit (HCT) using the following 

formula: 

HCT = MCV (fl) number of erythrocytes (10 6 /µl). 

Calculation of Erythrocyte Parameters 

The quality of erythrocytes is characterized by their MCV, their mean cell 

hemoglobin content (MCH), and the mean cellular hemoglobin concentration 

(MCHC). 

MCV is measured directly using an automated hemoglobin analyzer, or 

is calculated as follows: 

MCV 

Hematocrit (l/l) 

Number of erythrocytes (10 6 /µl) 

MCH (in picograms per erythrocyte) is calculated using the following 

formula: 

Hemoglobin (g/l) 

MCH (pg) 

Number of erythrocytes (106 /µl) 



MCHC is determined using this formula: 

MCHC (g/dl) 

Hemoglobin concentration (g/dl) 

Hematocrit (l/l) 

Red Cell Distribution Width (RDW) 

Modern analyzers also record the red cell distribution width (cell volume 

distribution). In normal erythrocyte morphology, this correlates with the 

Price-Jones curve for the cell diameter distribution. Discrepancies are 

used diagnostically and indicate the presence of microspherocytes 

(smaller cells with lighter central pallor). 

Reticulocyte Count 


Reticulocytes can be counted using flow cytometry and is based on the 

light absorbed by stained aggregates of reticulocyte organelles. The data 

are recorded as the number of reticulocytes per mill (‰) of the total number 

of erythrocytes. Reticulocytes can, of course, be counted in a counting 

chamber using a microscope. While this method is not particularly 

laborious, it is mostly employed in laboratories that often deal with or 

have a special interest in anemia. Reticulocytes are young erythrocytes 

immediately after they have extruded their nuclei: they contain, as a remainder 

of aggregated cell organelles, a net-like structure (hence the 

name “reticulocyte”) that is not discernible after the usual staining procedures 

for leukocytes, but can be observed after vital staining of cells 

with brilliant cresyl blue or new methylene blue. The staining solution is 

mixed in an Eppendorf tube with an equal volume of EDTA blood and incubated 

for 30 minutes. After repeated mixing, a blood smear is prepared 

and allowed to dry. The sample is viewed using a microscope equipped 

with an oil immersion lens. The ratio of reticulocytes to erythrocytes is determined 

and plotted as reticulocytes per 1000 erythrocytes (per mill). 

Normal values are listed in Table 2, p. 12. 



11

12 

Table 2 Normal ranges and mean values for blood cell components* 

Adults Newborns Toddlers Children 

18 years old 1 months 2 years old 10 years old 


MV 7000 11000 10000 8000 

NR 4300–10000 

Leukocytes/µl 

or 106 /l** 

Band granulocytes % MV 2 5 3 3 

NR 0–5 

Segmented neutrophilic MV 60 30 30 30 

granulocytes 

NR 35–85 

absolute ct./µl MV 3650 3800 3500 4400 

or 106 /l** NR 1850–7250 

Lymphocytes % MV 30 55 60 40 

NR 20–50 

absolute ct./µl MV 2500 6000 6300 3100 

or 106 /l** NR 1500–3500 

Monocytes % MV 4 6 5 4 

absolute ct./µl NR 2–6 

or 106 /l** MV 450 

NR 70–840 

Eosinophilic granulocytes (%) MV 2 3 2 2 

NR 0–4 

absolute ct./µl MV 165 

or 106 /l** NR 0–400 



Basophilic granulocytes (%) MW 0.5 0.5 0.5 0.5 

NR 0–1 

Male Female 

MV 5.4 4.8 4.7 4.7 4.8 

NR 4.6–5.9 4.2–5.4 3.9–5.9 3.8–5.4 3.8–5.4 

Erythrocytes 106 /µl 

or 1012 /l** 

MV 15 13 17 12 14 

NR 14–18 12–16 15–18 11–13 12–15 

Hb g/dl 

or 10 g/l** 

HKT MV 0.45 0.42 44 37 39 

NR 0.42–0.48 0.38–0.43 


MCH HbE (pg) MV 29 33 27 25 

NR 26–32 

MV 87 91 78 80 

NR 77–99 

MCV/µm3 or fl** 

MV 33 35 33 34 

NR 33–36 

MCHC g/dl 

or 10 g/l 

Erythrocyte, diameter (µm) MV 7.5 8.1 7.3 7.4 

Reticulocytes (%) MV 16 24 7.9 7.1 7.6 

NR 8–25 8–40 



Thrombocytes 103 /µl MV 180 155–566 286–509 247–436 

NR 140–440 

13 

MV mean value, NR normal range (range for 95% of the population, reference range), ct. count, ** SI units give the measurements per liter. 

* For technical reasons, data may vary considerably between laboratories. It is therefore important also to consult the reference ranges of the chosen laboratory.

14 


Leukocyte Count 

Leukocytes, unlike erythrocytes, are completely colorless in their native 

state. Another important physical difference is the stability of leukocytes 

in 3% acetic acid or saponins; these media hemolyze erythrocytes (though 

not their nucleated precursors). Türk’s solution, used in most counting 

methods, employs glacial acetic acid for hemolysis and crystal violet (gentian 

violet) to lightly stain the leukocytes. A 50-µl EDTA blood sample is 

mixed with 500 µl Türk’s solution in an Eppendorf tube and incubated at 

room temperature for 10 minutes. The suspension is again mixed and 

carefully transferred to the well of a prepared counting chamber using a 

pipette or capillary tube. The chamber is allowed to fill from a droplet 

placed at one edge of the well and placed in a moisture-saturated incubator 

for 10 minutes. With the condenser lowered (or using phase contrast 

microscopy), the leukocytes are then counted in a total of four of the large 

squares opposite to each other (1 mm 2 each). The result is multiplied by 

27.5 (dilution: 1 + 10, volume: 0.4 mm 3 ) to yield the leukocyte count per 

microliter. Parallel (control) counts show variation of up to 15%. The normal 

(reference) ranges are given in Table 2. 

In an automated blood cell counter, the erythrocytes are lysed and cells 

with a volume that exceeds about 30 fl (threshold values vary for different 

instruments) are counted as leukocytes. Any remaining erythroblasts, 

hard-to-lyse erythrocytes such as target cells, giant thrombocytes, or agglutinated 

thrombocytes are counted along with the leukocytes, and this 

will lead to an overestimate of the leukocyte count. Modern analyzers can 

recognize such interference factors and apply interference algorithms to 

obtain a corrected leukocyte count. 

Visual leukocyte counts using a counting chamber show a variance of 

about 10%; they can be used as a control reference for automatic cell 

counts. Rough estimates can also be made by visual assessment of blood 

smears: a 40 objective will show an average of two to three cells per field 

of view if the leukocyte count is normal. 



Thrombocyte Count 


15 

To count thrombocytes in a counting chamber, blood must be conditioned 

with 2% Novocain–Cl solution. Preprepared commercial tubes are widely 

used (e.g., Thrombo Plus with 2-ml content). EDTA blood is pipetted into 

the tubes, carefully mixed and immediately placed in a counting chamber. 

The chamber is allowed to stand for 10 minutes while the cells settle, 

after which an area of 1 mm 2 is counted. The result corresponds to the 

number of thrombocytes (the 1 + 100 dilution is ignored). In an automated 

blood cell counter, the blood cells are counted after they have been sorted 

by size. Small cells between 2 and 20 fl (thresholds vary for different instruments) 

are counted as thrombocytes. If giant thrombocytes or agglutinated 

thrombocytes are present, they are not counted and the result is an 

underestimate. On the other hand, small particles, such as fragmentocytes, 

or microcytes, will lead to an overestimate. Modern analyzers can 

recognize such interference factors and apply interference algorithms to 

obtain a corrected thrombocyte count. If unexpected results are produced, 

it is wise to check them by direct reference to the blood smear. 

Unexpected thrombocyte counts should be verified by direct visual 

assessment. Using a 100 objective, the field of view normally contains 

an average of 10 thrombocytes. In some instances, “pseudothrombocytopenias” 

are found in automated counts. These are artifacts due to thrombocyte 

aggregation. 

Pseudothrombocytopenia (see p. 167) is caused by the aggregation of 

thrombocytes in the presence of EDTA; it does not occur when heparin or 

citrate are used as anticoagulants. 

Quantitative Normal Values and Range of 

Cellular Blood Components 

Determining normal values for blood components is more difficult and 

more risky than one might expect. Obviously, the values are affected by a 

large number of variables, such as age, gender, activity (metabolic load), 

circadian rhythm, and nutrition, not to mention the effects of the blood 

sampling technique, type and storage of the blood, and the counting 

method. For this reason, where available, a normal range is given, covering 

95% of the values found in a clinically normal group of probands—from 

which it follows that one in every 20 healthy people will have values outside 

the limits of this range. Thus, there are areas of overlap between normal 

and pathological data. Data in these borderline areas must be interpreted 

within a refined reference range with data from probands who 



16 

Leukocyte count (10 9 /l) 

22 

20 

18 

16 

14 

12 

10 

8 

6 

4 

2 

0 


resemble each other and the patient as closely as possible in respect of the 

variables listed above. Due to space limitations, only key age data are considered 

here. Figure 3 clearly shows that, particularly for newborns, toddlers, 

and young children, particular reference ranges must be taken into 

account. In addition, the interpretation must also take account of 

methodological variation: in cell counts, the coefficient of variation (standard 

deviation as a percentage of the mean value) is usually around 10! 

Hours 

12 2 4 6 1 2 3 5 3 6 9 1 3 5 7 9 11 13 

Days 

Weeks 

Months 

Years 

Leukocytes 

Granulocytes 

Lymphocytes 

Monocytes 

Fig. 3 Mean cell counts at different ages in childhood for leukocytes and their 

subfractions (according to Kato) 




In sum, a healthy distrust for the single data point is the most important 

basis for the interpretation of all data, including those outside the reference 

range. For every sample of drawn blood, and every counting 

method, at least two or three values should be available before conclusions 

can be drawn, unless the clinical findings reflect the cytological data. 

In addition to this, every laboratory has its own set of reference data to 

some extent. 

17 

After this account of the problems and wide variations between different 

groups, the data in Table 2 are presented in a simplified form, with values 

rounded up or down for ease of comparison and memorization. Absolute 

values and the new SI units are given where they are clinically relevant. 

The Blood Smear and Its Interpretation 

(Differential Blood Count, DBC) 

A blood smear uses capillary or venous EDTA-blood, preferably no more 

than three hours old. The slides must be grease-free, otherwise cell aggregation 

and stain precipitation may occur. Unless commercially available 

grease-free slides are used, the slides should be soaked for several hours in 

a solution of equal parts of ethanol and ether and then allowed to dry. A 

droplet of the blood sample is placed close to the edge of the slide. A 

ground cover glass (spreader slide) is placed in front of the droplet onto 

the slide at an angle of about 30. The cover slide is then slowly backed into 

the blood droplet. Upon contact, the blood droplet spreads along the edge 

of the slide (Fig. 4). Without pressure, the cover glass is now lightly moved 

over the slide. The faster the cover glass is moved, and the steeper angle at 

which it is held, the thinner the smear will be. 

The quality of the smear technique is crucial for the assessment, because 

the cell density at the end of the smear is often twice that at the beginning. 

In a well-prepared smear the blood sample will show a “feathered” edge 

where the cover glass left the surface of the slide. The smear must be 

thoroughly air-dried; for good staining, at least two hours’ drying time is 

needed. The quality of the preparation will be increased by 10 minutes’ 

fixation with methanol, and it will then also keep better. After drying, 

name and date are pencilled in on the slide. 



18 


Fig. 4 Preparation of a blood smear 

For safety’s sake, at least one back-up smear should be made from every 

sample from every patient. 

Staining is done with a mixture of basic stains (methylene blue, azure) and 

acidic stains (eosin), so as to show complementary substances such as nucleic 

acids and alkaline granulations. In addition to these leukocyte components, 

erythrocytes also yield different staining patterns: immature 

erythrocytes contain larger residual amounts of RNA and therefore stain 

more heavily with basophilic stains than do mature erythrocytes. Pappenheim’s 

panoptic stain contains a balanced mixture of basic and acidic 

stains: the horizontally stored, air-dried smear is covered with May– 

Grünwald staining solution (eosin–methylene blue) for three minutes, 

then about an equal amount of phosphate buffer, pH = 7.3, is carefully 

added and, after a further three minutes, carefully poured off again. Next, 

the slide is covered with diluted Giemsa stain (azure–eosin), which is prepared 

by addition of 1 ml Giemsa stock solution to 1 ml neutral distilled 

water or phosphate buffer, pH = 6.8–7.4. After 15 minutes, the Giemsa 

staining solution is gently rinsed off with buffer solution and the smears 

are air-dried with the feathered end sloping upwards. 

The blood smears are initially viewed with a smaller objective (10 to 

20), which allows the investigator to check the cell density and to find 

the best counting area in the smear. Experience shows that the cell projection 

is best about 1 cm from the feathered end of the smear. At 40 magnification, 

one may expect to see an average of two to three leukocytes per 

viewing field if the leukocyte count is normal. It is sometimes useful to be 

able to use this rough estimate to crosscheck improbable quantitative 

values. The detailed analysis of the white blood cells is done using an oil 

immersion lens and 100 magnification. For this, it is best to scan the sec- 




19 

tion from about 1 cm to about 3 cm from the end of the smear, moving the 

slide to and fro in a meandering movement across its short diameter. 

Before (and while) the differential leukocyte count is carried out, erythrocyte 

morphology and thrombocyte density should be assessed. The results 

of the differential leukocyte count (the morphologies are presented in the 

atlas section, p. 30 ff.) may be recorded using manual counters or mark-up 

systems. The more cells are counted, the more representative the results, 

so when pathological deviations are found, it is advisable to count 200 

cells. 

To speed up the staining process, which can seem long and laborious 

when a rapid diagnosis is required, several quick-staining sets are available 

commercially, although most of them do not permit comparable fine 

analysis. If the standard staining solutions mentioned above are to hand, a 

quick stain for orientation purposes can be done by incubating the smear 

with May–Grünwald reagent for just one minute and shortening the 

Giemsa incubation time to one to two minutes with concentrated “solution.” 

Normal values and ranges for the differential blood count are given in 

Table 2, p. 12. 

Malaria plasmodia are best determined using a thick smear in addition 

to the normal blood smear. On a slide, a drop of blood is spread over an 

area of about 2.5 cm across. The thick smear is placed in an incubator and 

allowed to dry for at least 30 minutes. Drying samples as thick smears and 

then treating them with dilute Giemsa stain (as described above) achieves 

extensive hemolysis of the erythrocytes and thus an increase in the released 

plasmodia. 

Significance of the Automated Blood Count 

The qualitative and quantitative blood count techniques described here 

may seem somewhat archaic given the now almost ubiquitous automated 

cell counters; they are merely intended to show the possibilities always 

ready to be called on in terms of individual analyses carried out by small, 

dedicated laboratories. 

The automated cell count has certainly rationalized blood cell counting. 

Depending on the diagnostic problem and the quality control system of 

the individual laboratory, automated counting can even reduce data 

ranges compared with “manual” counts. 

After lysis of the erythrocytes, hematology analyzers determine the number 

of remaining nucleated cells using a wide range of technologies. All 

counters use cell properties such as size, interaction with scattered light at 

different angles, electrical conductivity, nucleus-to-cytoplasm ratio, and 



20 


the peroxidase reaction, to group individual cell impulses into clusters. 

These clusters are then quantified and assigned to leukocyte populations. 

If only normal blood cells are present, the assignment of the clusters to 

the various leukocyte populations works well, and the precision of the automated 

count exceeds that of the manual count of 100 cells in a smear by 

a factor of 10. If large number of pathological cells are present, such as 

blasts or lymphadenoma cells, samples are reliably recognized as “pathological,” 

and a smear can then be prepared and further analyzed under the 

microscope. 

The difficulty arises when small populations of pathological cells are 

present (e.g., 2% blasts present after chemotherapy), or when pathological 

cells are present that closely resemble normal leukocytes (e.g., small centrocytes 

in satellite cell lymphoma). These pathological conditions are not 

always picked up by automated analyzers (false negative result), no smear 

is prepared and studied under the microscope, and the results produced 

by the machine do not include the presence of these pathological populations. 

For this reason, blood samples accompanied by appropriate clinical 

queries (e.g., “lymphadenoma?” “blasts?” “unexplained anemia?”) should 

always be differentiated and evaluated using a microscope. 

Bone Marrow Biopsy 

Occasionally, a disease of the blood cell system cannot be diagnosed and 

classified on the basis of the blood count alone and a bone marrow biopsy 

is indicated. In such cases it is more important to perform this biopsy competently 

and produce good smears for evaluation than to be able to interpret 

the bone marrow cytology yourself. Indications for bone marrow 

biopsy are given in Table 3. 

In the attempt to avoid complications, the traditional location for bone 

marrow biopsy at the sternum has been abandoned in favor of the superior 

part of the posterior iliac spine (back of the hipbone) (Fig. 5). 

Although the bone marrow cytology findings from the aspirate are sufficient 

or even preferable for most hematological questions (see Table 3), it 

is regarded as good practice to obtain a sample for bone marrow histology 

at the same time, since with improved instruments the procedure 

has become less stressful, and complementary cytological and histological 

data are then available from the start. After deep local anesthesia of the 

dorsal spine and a small skin incision, a histology cylinder at least 1.5 cm 

long is obtained using a sharp hollow needle (Yamshidi). A Klima and Rossegger 

cytology needle (Fig. 5) is then placed through the same subcutaneous 

channel but at a slightly different site from the earlier insertion 

point on the spine and gently pushed through the compacta. The mandrel 




is pulled out and a 5- to 10-ml syringe body with 0.5 ml citrate or EDTA 

(heparin is used only for cytogenetics) is attached to the needle. The 

patient should be warned that there will be a painful drawing sensation 

during aspiration, which cannot be avoided. The barrel is then slowly 

pulled, and if the procedure is successful, blood from the bone marrow fills 

the syringe. The syringe body is separated from the needle and the mandrel 

reintroduced. The bone marrow aspirate is transferred from the syringe 

to a Petri dish. When the dish is gently shaken, small, pinhead-sized 

bone marrow spicules will be seen lying on the bottom. A smear, similar to 

a blood smear, can be prepared on a slide directly from the remaining contents 

of the syringe. If the first aspirate has obtained material, the needle is 

removed and a light compression bandage is applied. 

If the aspirate for cytology contains no bone marrow fragments (“punctio 

sicca,” dry tap), an attempt may be made to obtain a cytology smear 

from the (as yet unfixed) histology cylinder by rolling it carefully on the 

slide, but this seldom produces optimal results. 

The preparation of the precious bone marrow material demands 

special care. One or two bone marrow spicules are pushed to the outer 

edge of the Petri dish, using the mandrel from the sternal needle, a needle, 

or a wooden rod with a beveled tip, and transferred to a fat-free microscopy 

slide, on which they are gently pushed to and fro by the needle along 

the length of the slide in a meandering line. This helps the analyzing 

Fig. 5 Bone marrow biopsy from the superior part of the posterior iliac spine 

(back of the hipbone) 



21

22 


Fig. 6 Squash preparation and meandering smear for the cytological analysis of 

bone marrow spicules 

technician to make a differentiatial count. It should be noted that too 

much blood in the bone marrow sample will impede the semiquantitative 

analysis. In addition to this type of smear, squash preparations should also 

be prepared from the bone marrow material for selective staining. To do 

this, a few small pieces of bone marrow are placed on a slide and covered 

by a second slide. The two slides are lightly pressed and slid against each 

other, then separated (see Fig. 6). 

The smears are allowed to air-dry and some are incubated with panoptic 

Pappenheim staining solution (see previous text). Smears being sent to 

a diagnostic laboratory (wrapped individually and shipped as fragile 

goods) are better left unstained. Fresh smears of peripheral blood should 

accompany the shipment of each set of samples. (For principles of analysis 

and normal values see p. 52 ff., for indications for bone marrow cytology 

and histology see p. 27 ff.) 




Lymph Node Biopsy and Tumor Biopsy 

23 

These procedures, less invasive than bone marrow biopsy, are a simple 

and often diagnostically sufficient method for lymph node enlargement or 

other intumescences. The unanesthetized, disinfected skin is sterilized 

and pulled taut over the node. A no. 1 needle on a syringe with good suction 

is pushed through the skin into the lymph node tissue (Fig. 7). Tissue 

is aspirated from several locations, changing the angle of the needle 

slightly after each collection, and suction maintained while the needle is 

withdrawn into the subcutis. Aspiration ceases and the syringe is removed 

without suction. The biopsy harvest, which is in the needle, is extruded 

onto a microscopy slide and smeared out without force or pressure using a 

cover glass (spreader slide). Staining is done as described previously for 

blood smears. 



24 

1. 

Skin puncture 

2. 

Aspiration 

3. 

Collecting 

aspirates from 

different lymph 

node locations 

4. 

Detaching the 

syringe body, 

equalizing the 

pressure difference 

5. 

Removal of the 

syringe body and 

cannula 

6. 

Pulling back the 

syringe barrel 

7. 

Pushing the 

biopsy material 

onto a slide 


Fig. 7 Procedure for 

lymph node biopsy 



Step-by-Step Diagnostic Sequence 


On the basis of what has been said so far, the following guidelines for the 

diagnostic workup of hematological changes may be formulated: 

25 

1. The first step is quantitative determination of leukocytes (L), erythrocytes 

(E) and thrombocytes (T). Because the normal range can vary so widely 

in individual cases (Table 2), the following rule of thumb should be observed: 

A complete blood count (CBC) should be included in the baseline data, 

like blood pressure. 

2. All quantitative changes in L + E + T call for a careful evaluation of the 

differential blood count (DBC). Since clinical findings determine 

whether a DBC is indicated, it may be said that: 

A differential blood count is indicated: 

➤ By all unexplained clinical symptoms, especially 

➤ Enlarged lymph nodes or splenomegaly 

➤ Significant changes in any of 

– Hemoglobin content or number of erythrocytes 

– Leukocyte count 

– Thrombocyte count 

The only initial assumption here is that mononuclear cells with unsegmented 

nuclei can be distinguished from polynuclear cells. While this 

nomenclature may not conform to ideal standards, it is well established 

and, moreover, of such practical importance as a fundamental distinguishing 

criterion that it is worth retaining. A marked majority of 

mononuclear cells over the polynuclear segmented granulocytes is an 

unambiguous early finding. 

The next step has to be taken with far more care and discernment: 

classifying the mononuclear cells according to their possible origin, lymphatic 

cells, monocytes, or various immature blastic elements, which 

otherwise only occur in bone marrow. The aim of the images in the 

Atlas section of this book is to facilitate this part of the differential diagnosis. 

To a great extent, the possible origins of mononuclear cells can be 

distinguished; however, the limits of morphology and the vulnerability 

to artifacts are also apparent, leaving the door wide open to further 



26 


diagnostic steps (specialist morphological studies, cytochemistry, 

immunocytochemistry. A predominance of mononuclear cell elements 

has the same critical significance in the differential diagnosis of both 

leukocytoses and leukopenias. 

3. After the evaluation of the leukocytes, assessment of erythrocyte morphology 

is a necessary part of every blood smear evaluation. It is, naturally, 

particularly important in cases showing disturbances in the 

erythrocyte count or the hemoglobin. 

4. After careful consideration of the results obtained so far and the 

patient's clinical record, the last step is the analysis of the cell composition 

of the bone marrow. Quite often, suspected diagnoses are confirmed 

through humoral tests such as electrophoresis, or through cytochemical 

tests such as alkaline phosphatase, myeloperoxidase, nonspecific 

esterase, esterase, or iron tests. 

Bone marrow analysis is indicated when clinical findings and blood 

analysis leave doubts in the diagnostic assessment, for example in 

cases of: 

➤ Leukocytopenia 

➤ Thrombocytopenia 

➤ Undefined anemia 

➤ Tricytopenia, or 

➤ Monoclonal hypergammaglobulinemia 

A bone marrow analysis may be indicated in order to evaluate the 

spreading of a lymphadenoma or tumor, unless the bloodstream already 

shows the presence of pathological cells. 

5. Bone marrow histology is also rarely indicated (even more rarely than 

the bone marrow cytology). Examples of the decision-making process 

between bone marrow cytology and histology (biopsy) are shown in 

Table 3. 

Often only histological analysis can show structural changes or focal infiltration 

of the bone marrow. 

This is particularly true of the frequently fiber-rich chronic myeloproliferative 

diseases, such as polycythemia vera rubra, myelofibrosis– 

osteomyelosclerosis (MF-OMS), essential thrombocythemia (ET), and 

chronic myeloid leukemia (CML) as well as malignant lymphoma 

without hematological involvement (Hodgkin disease or blastic non- 

Hodgkin lymphoma) and tumor infiltration. 



Table 3 Indications for a differential blood count (DBC), bone marrow aspiration, and biopsy 

Indications Procedures 

All clinically unclear situations: 

➤ Enlarged lymph nodes or spleen 

➤ Changes in the simple CBC (penias or 

cytoses) 

➤ When a diagnosis cannot be made based on 

clinical findings and analysis of peripheral 

blood differential blood analysis, cytochemistry, 

phenotyping, molecular genetics or 

FISH 


Differential blood count (DBC) 

Bone marrow analysis 

Bone marrow aspirate 

(Morphology, phenotyping, 

cytogenetics, FISH, 

molecular genetics) 

Bone marrow 

trephine biopsy 

(Morphology, immunohistology) 

➤ Punctio sicca ("dry tap") not possible + 

➤ Aplastic bone marrow not possible + 

➤ Suspicion of myelodysplastic syndrome + (+) (e. g. hypoplasia) 

➤ Pancytopenia + + 

➤ Anemia, isolated + – 

➤ Granulocytopenia, isolated + – 

➤ Thrombocytopenia, isolated (except ITP) + – 

➤ Suspected ITP (+) For therapy failure – 

➤ Suspected OMF/OMS – (BCR-ABL in peripheral 

blood is sufficient) 

+ 

➤ Suspected PV – (BCR-ABL in peripheral 


– 

➤ Suspected ET – (BCR-ABL in peripheral 


+ 

➤ Suspected CML – (BCR-ABL in peripheral (+) Conditions for the 

blood is sufficient) analysis 

➤ CMPE (BCR-ABL negative) (+) Differential diagnoses + 

➤ Suspected AL/AL + (+) Not in typical cases 

➤ Suspected bone marrow metastases – + 

➤ Monoclonal hypergammaglobulinemia + + 

➤ NHL (exceptions, see below) + + 

➤ Typical CLL + (+) Prognostic factor 

➤ Follicular lymphoma (+) To distinguish vs 

other NHL 

+ 

➤ Hodgkin disease – + 

Further indications for a bone marrow analysis are: 

➤ Unexplained hypercalcemia + + 

➤ Inexplicable increase of bone AP – + 

➤ Obvious, unexplained abnormalities – + 

➤ Hyperparathyroidism – + 

➤ Paget disease – + 

➤ Osteomalacia – + 

➤ Renal osteopathy – + 

➤ Gaucher syndrome – + 

+ Recommended, – not recommended, (+) conditionally recommended, ITP idiopathic thrombocytopenia, 

OMF/OMS osteomyelofibrosis/osteomyelosclerosis, PV polycythemia vera, ET essential thrombocythemia, 

CMPD chronic myeloproliferative disorders, AL acute leukemia, NHL non-Hodgkin lymphoma, CLL chronic 

lymphocytic leukemia, FISH fluorescence in situ hybridization, AP alkaline phosphatase. 



27

28 



Normal Cells of the Blood and 

Hematopoietic Organs 



30 

Normal Cells of the Blood and Hematopoietic Organs 

The Individual Cells of Hematopoiesis 

Immature Red Cell Precursors: Proerythroblasts and 

Basophilic Erythroblasts 

Proerythroblasts are the earliest, least mature cells in the erythrocyteforming 

series (erythropoiesis). Proerythroblasts are characterized by 

their size (about 20 µm), and by having a very dense nuclear structure 

with a narrow layer of cytoplasm, homogeneous in appearance, with a 

lighter zone at the center; they stain deep blue after Romanowsky staining. 

These attributes allow proerythroblasts to be distinguished from 

myeloblasts (p. 35) and thus to be assigned to the erythrocyte series. After 

mitosis, their daughter cells display similar characteristics except that 

they have smaller nuclei. Daughter cells are called basophilic erythroblasts 

(formerly also called macroblasts). Their nuclei are smaller and the chromatin 

is more coarsely structured. 

The maturation of cells in the erythrocyte series is closely linked to the 

activity of macrophages (transformed monocytes), which phagocytose 

nuclei expelled from normoblasts and iron from senescent erythrocytes, 

and pass these cell components on to developing erythrocytes. 

Diagnostic Implications. Proerythrocytes exist in circulating blood only 

under pathological conditions (extramedullary hematopoiesis; breakdown 

of the blood–bone marrow barrier by tumor metastases, p. 150; or 

erythroleukemia, p. 100). In these situations, basophilic erythroblasts may 

also occur; only exceptionally in the course of a strong postanemia regeneration 

will a very few of these be released into the blood stream (e.g., 

in the compensation phase after severe hemorrhage or as a response to 

vitamin deficiency, see p. 152). 



Normally erythropoiesis takes place only in the bone marrow 

a b 

Fig. 8 Early erythropoiesis. a The earliest recognizable red cell precursor is the 

large dark proerythroblast with loosely arranged nuclear chromatin (1). Below are 

two orthochromatic erythroblasts (2), on the right a metamyelocyte (3). b Proerythroblast 

(1). c Proerythroblast (1) next to a myeloblast (2) (see p. 34); lower 

region of image shows a promyelocyte (3). Toward the upper left are a metamyelocyte 

(4) and a segmented neutrophilic granulocyte (5). 



31 

c

32 


Mature Red Blood Precursor Cells: Polychromatic 

and Orthochromatic Erythroblasts (Normoblasts) 

and Reticulocytes 

The results of mitosis of erythroblasts are called normoblasts. This name 

covers two cell types with relatively dense round nuclei and grayish pink 

stained cytoplasm. The immature cells in which the cytoplasm displays a 

grayish blue hue, which are still able to divide, are now called “polychromatic 

erythroblasts,” while the cells in which the cytoplasm is already 

taking on a pink hue, which contain a lot of hemoglobin and are no longer 

able to divide, are called “orthochromatic erythroblasts.” The nuclei of the 

latter gradually condense into small black spheres without structural definition 

that eventually are expelled from the cells. The now enucleated 

young erythrocytes contain copious ribosomes that precipitate into reticular 

(“net-like”) structures after special staining (see p. 11), hence their 

name, reticulocytes. 

To avoid confusing erythroblasts and lymphoblasts (Fig. 9 d), note the 

completely rounded, very dense normoblast nuclei and homogeneous, 

unstructured cytoplasm of the erythroblasts. 

Diagnostic Implications. Polychromatic and orthochromatic erythroblasts 

may be released into the bloodstream whenever hematopoiesis is activated, 

e.g., in the compensation or treatment stage after hemorrhage or 

iron or vitamin deficiency. They are always present when turnover of 

blood cells is chronically increased (hemolysis). Once increased blood regeneration 

has been excluded, the presence of erythroblasts in the blood 

should prompt consideration of two other disorders: extramedullary production 

of blood cells in myeloproliferative diseases (p. 114), and bone 

marrow carcinosis with destruction of the blood–bone marrow barrier 

(p. 154). In the same situations, the reticulocyte counts (after special staining) 

are elevated above the average of 25‰ for men and 40‰ for women, 

respectively, and can reach extremes of several hundred per mill. 

Fig. 9 Nucleated erythrocyte precursors. a Two basophilic erythroblasts with 

condensed chromatin structure (1) and a polychromatic erythroblast with an almost 

homogeneous nucleus (2). b The erythropoiesis in the bone marrow is often 

organized around a macrophage with a very wide, light cytoplasmic layer (1). 

Grouped around it are polychromatic erythroblasts of variable size. Erythroblast 

mitosis (2). c Polychromatic erythroblast (1) and orthochromatic erythroblast 

(normoblast) (2). 



a b 

c 

d 

During increased turnover, nucleated red cell precursors may 

migrate into the peripheral blood 

Fig. 9 d The density of the nuclear chromatin is similar in lymphocytes (1) and 

erythroblasts (2), but in the erythroblast the cytoplasm is wider and similar in color 

to a polychromatic erythrocyte (3). e Normal red blood cell findings with slight 

variance in size of the erythrocytes. A lymphocyte (1) and a few thrombocytes (2) 

are seen. The erythrocytes are slightly smaller than the nucleus of the lymphocyte 

nucleus. 



33 

e

34 


Immature White Cell Precursors: Myeloblasts and 

Promyelocytes 

Myeloblasts are the least mature cells in the granulocyte lineage. Mononuclear, 

round-to-ovoid cells, they may be distinguished from proerythroblasts 

by the finer, “grainy” reticular structure of their nuclei and the 

faintly basophilic cytoplasm. On first impression, they may look like large 

or even small lymphocytes (micromyeloblasts), but the delicate structure 

of their nuclei always gives them away as myeloblasts. In some areas, condensed 

chromatin may start to look like nucleoli. Sporadically, the cytoplasm 

contains azurophilic granules. 

Promyelocytes are the product of myeloblast division, and usually grow 

larger than their progenitor cells. During maturation, their nuclei show an 

increasingly coarse chromatin structure. The nucleus is eccentric; the 

lighter zone over its bay-like indentation corresponds to the Golgi apparatus. 

The wide layer of basophilic cytoplasm contains copious large 

azurophilic granules containing peroxidases, hydrolases, and other 

enzymes. These granulations also exist scattered all around the nucleus, as 

may be seen by focusing on different planes of the preparation using the 

micrometer adjustment on the microscope. 

Diagnostic Implications. Ordinarily, both cell types are encountered only 

in the bone marrow, where they are the most actively dividing cells and 

main progenitors of granulocytes. In times of increased granulocyte production, 

promyelocytes and (in rare cases) myeloblasts may be released 

into the blood stream (pathological left shift, see p. 112). Under strong regeneration 

pressure from the erythrocyte series, too—e.g., during the 

compensation phase following various anemias—immature white cell 

precursors, like the red cell precursors, may be swept into the peripheral 

blood. Bone marrow involvement by tumor metastases also increases the 

permeability of the blood–bone marrow barrier for immature white cell 

precursors (for an overview, see p. 112 ff.). 

In some acute forms of leukemia, myeloblasts (and also, rarely, promyelocytes) 

dominate the blood analysis (p. 97). 



Round cells with “grainy” reticular chromatin structure are 

blasts, not lymphocytes 

a b 

c d 

Fig. 10 Granulocyte precursors. a The least mature precursor in granulopoiesis 

is the myeloblast, which is released into the blood stream only under pathological 

conditions. A large myeloblast is shown with a fine reticular nuclear structure and 

a narrow layer of slightly basophilic cytoplasm without granules. b Myeloblast and 

neutrophilic granulocytes with segmented nuclei (blood smear from a patient 

with AML). c Myeloblast (1), which shows the start of azurophilic granulation 

(arrow), and a promyelocyte (2) with copious large azurophilic granules, typically 

in a perinuclear location. d Large promyelocyte (1), myelocyte (2), metamyelocyte 

(3), and polychromatic erythroblast (4). 

35 



36 


Partly Mature White Cell Precursors: Myelocytes and 

Metamyelocytes 

Myelocytes are the direct product of promyelocyte mitosis and are always 

clearly smaller than their progenitors. The ovoid nuclei have a banded 

structure; the cytoplasm is becoming lighter with maturation and in some 

cases acquiring a pink tinge. A special type of granules, which no longer 

stain red like the granules in promyelocytes (“specific granules,” peroxidase-negative), 

are evenly distributed in the cytoplasm. Myelocyte morphology 

is wide-ranging because myelocytes actually cover three different 

varieties of dividing cells. 

Metamyelocytes (young granulocytes) are the product of the final myelocyte 

division and show further maturation of the nucleus with an increasing 

number of stripes and points of density that give the nuclei a spotted 

appearance. The nuclei slowly take on a kidney bean shape and have some 

plasticity. Metamyelocytes are unable to divide. From this stage on, only 

further maturation of the nucleus occurs by contraction, so that the distinctions 

(between metamyelocytes, band neutrophils, and segmented 

neutrophils) are merely conventional, although they do relate to the varying 

“maturation” of these cell forms. 

Diagnostic Implications. Like their precursors, myelocytes and metamyelocytes 

normally appear in the peripheral blood only during increased 

cell production in response to stress or triggers, especially infections (for 

an overview of possible triggers, see p. 112). Under these conditions, they 

are, however, more abundant than myeloblasts or promyelocytes. 



a b 

c 

Myelocytes and metamyelocytes also occur in the blood stream 

in severe reactive disease 

Fig 11 Myelocytes and metamyelocytes. a Early myelocyte. The chromatin 

structure is denser than that of promyelocytes. The granules do not lie over the 

nucleus (as can be seen by turning the fine focus adjustment of the microscope to 

and fro). The blood smear is from a case of sepsis, hence the intensive granulation. 

b Slightly activated myelocyte (the cytoplasm is still relatively basophilic). c Typical 

myelocyte (1) close to a segmented neutrophil (2). d This metamyelocyte is 

distinguished from a myelocyte by incipient lobe formation. 



37 

d

38 


Mature Neutrophils: Band Cells and Segmented 

Neutrophils 

Band cells (band neutrophils) represent the further development of 

metamyelocytes. Distinguishing between the different cell types is often 

difficult. The term “band cell” should be used when all nuclear sections of 

the nucleus are approximately the same width (the “bands”). The beginnings 

of segmentation may be visible, but the indentations should never 

cut more than two-thirds of the way across the nucleus. 

Segmented neutrophils represent the final stage in the lineage that started 

with myeloblasts, forming gradually, without any clear transition or 

further cell divisions, by increasing contraction of their nuclei. Finally, the 

nuclear segments are connected only by narrow chromatin bridges, which 

should be no thicker than one-third of the average diameter of the nucleus. 

The chromatin in each segment forms coarse bands, or patches and 

is denser than the chromatin in band neutrophils. 

The cytoplasm of segmented neutrophilic granulocytes varies after 

staining from nearly colorless to soft pink or violet. The abundant granules 

are often barely visible dots. 

The number of segments increases with the age of the cells. The following 

approximate values are taken to represent a normal distribution: 

10–30% have two segments, 40–50% have three segments, 10–20% have 

four segments, and 0–5% of the nuclei have five segments. A left shift to 

smaller numbers of segments is a discreet symptom of reactive activation 

of this cell series. A right shift to higher numbers of segments (oversegmentation) 

usually accompanies vitamin B12 and folic acid deficiencies. 

Diagnostic Implications. Banded neutrophilic granulocytes (band neutrophils) 

may occur in small numbers (up to 2%) in a normal blood count. This 

is of no diagnostic significance. A higher proportion than 2% may indicate 

a left shift and constitute the first sign of a reactive condition (p. 113). The 

diagnostic value of segmented neutrophilic granulocytes (segmented 

neutrophils) is that normal values are the most sensitive diagnostic indicator 

of normally functioning hematopoiesis (and, especially, of normal 

cellular defense against bacteria). An increase in segmented neutrophils 

without a qualitative left shift is not evidence of an alteration in bone marrow 

function, because under certain conditions stored cells may be released 

into the peripheral blood (for causes, see p. 111). In conjunction 

with qualitative changes (left shift, toxic granulations), however, 

granulocytosis does in fact indicate bone marrow activation that may have 

a variety of triggers (pp. 110 f.), and if the absolute number has fallen 

below the lower limit of the normal range (Table 2, p. 12), a bone marrow 

defect or increased cell death must be considered. 



a b 

c 

Advancing nuclear contraction and segmentation: continuous 

transformation from metamyelocyte to band cell and then segmented 

neutrophilic granulocyte 

e 

Fig. 12 Neutrophils (neutrophilic granulocytes). a Transitional form between a 

metamyelocyte and a band cell. b Copious granulation in a band cell (1) (toxic granulation) 

next to band cells (2) with Döhle bodies (arrows). c Two band cells. 

d Band cells can also occur as aggregates. e Segmented neutrophilic granulocytes. 

f Segmented neutrophilic granulocyte after the peroxidase reaction. 

g Segmented neutrophilic granulocyte after alkaline leukocyte phosphatase (ALP) 

staining. 

39 



d 

f 

g

40 


Cell Degradation, Special Granulations, and Nuclear 

Appendages in Neutrophilic Granulocytes and Nuclear 

Anomalies 

Toxic granulation is the term used when the normally faint stippled 

granules in segmented neutrophils stain an intense reddish violet, usually 

against a background of slightly basophilic cytoplasm; unlike the normal 

granules, they stain particularly well in an acidic pH (5.4). This phenomenon 

is a consequence of activity against bacteria or proteins and is observed 

in serious infections, toxic or drug effects, or autoimmune 

processes (e.g., chronic polyarthritis). At the same time, cytoplasmic 

vacuoles are often found, representing the end stage of phagocytosis (especially 

in cases of sepsis), as are Döhle bodies: small round bodies of basophilic 

cytoplasm that have been described particularly in scarlet fever, 

but may be present in all serious infections and toxic conditions. A deficiency 

or complete absence of granulation in neutrophils is a sign of 

severe disturbance of the maturation process (e.g., in myelodysplasia or 

acute leukemia). The Pelger anomaly, named after its first describer, is a 

hereditary segmentation anomaly of granulocytes that results in round, 

rod-shaped, or bisegmented nuclei. The same appearance as a nonhereditary 

condition (pseudo-Pelger formation, also called Pel–Ebstein fever, or 

[cyclic] Murchison syndrome) indicates a severe infectious or toxic stress 

response or incipient myelodysplasia; it also may accompany manifest 

leukemia. 



Note the granulations, inclusions, and appendages in segmented 

neutrophilic granulocytes 

a b 

c d 

Fig. 13 Variations of segmented neutrophilic granulocytes. a Reactive state with 

toxic granulation of the neutrophilic granulocytes, more visibly expressed in the 

cell on the left (1) than the cell on the right (2) (compare with nonactivated cells, 

p. 39). b Sepsis with toxic granulation, cytoplasmic vacuoles, and Döhle bodies 

(arrows) in band cells (1) and a monocyte (2). c Pseudo-Pelger cell looking like 

sunglasses (toxic or myelodysplastic cause). d Döhle-like basophilic inclusion (arrow) 

without toxic granulation. Together with giant thrombocytes this suggests 

May–Hegglin anomaly. continued 

41 



42 


Nuclear appendages, which must not to be mistaken for small segments, 

are minute (less than the size of a thrombocyte) chromatin bodies that remain 

connected to the main part of the nucleus via a thin bridge and consequently 

look like a drumstick, sessile nodule, or small tennis racket. Of 

these, only the drumstick form corresponds to the X-chromosome, which 

has become sequestered during the process of segmentation. A proportion 

of 1–5% circulating granulocytes with drumsticks (at least 6 out of 500) 

suggests female gender; however, because the drumstick form is easy to 

confuse with the other (insignificant) forms of nuclear appendage, care 

should be taken before jumping to conclusions. 

Rarely, degrading forms of granulocytes, shortly before cytolysis or 

apoptosis, may be found in the blood (they are more frequent in exudates). 

In these, the segments of the nucleus are clearly losing connection, and the 

chromatin structure of the individual segments, which are becoming 

round, becomes dense and homogeneous. 

Diagnostic Implications. Toxic granulation indicates bacterial, chemical, or 

metabolic stress. Pseudo-Pelger granulocytes are observed in cases of infectious–toxic 

stress conditions, myelodysplasia, and leukemia. 

The use of nuclear appendages to determine gender has lost significance 

in favor of genetic testing. 



Note the granulations, inclusions, and appendages in segmented 

neutrophilic granulocytes 

e f 

g h 

Fig. 13 continued. e Hypersegmented neutrophilic granulocyte (six or more 

segments). There is an accumulation of these cells in megaloblastic anemia. f 

Drumstick (arrow 1) as an appendage with a thin filament bridge to the nucleus 

(associated with the X-chromosome), adjoined by a thrombocyte (arrow 2). g 

Very large granulocyte from a blood sample taken after chemotherapy. h Segmented 

neutrophilic granulocyte during degradation, often seen as an artifact after 

prolonged sample storage (more than eight hours). 



43

44 


Eosinophilic Granulocytes (Eosinophils) 

Eosinophils arise from the same stem cell population as neutrophils and 

mature in parallel with them. The earliest point at which eosinophils can 

be morphologically defined in the bone marrow is at the promyelocyte 

stage. Promyelocytes contain large granules that stain blue–red; not until 

they reach the metamyelocyte stage do these become a dense population 

of increasingly round, golden-red granules filling the cytoplasm. The 

Charcot–Leyden crystals found between groups of eosinophils in exudates 

and secretions have the same chemical composition as the eosinophil 

granules. 

The nuclei of mature eosinophils usually have only two segments. 

Diagnostic Implications. In line with their function (see p. 5) (reaction 

against parasites and regulation of the immune response, especially 

defense against foreign proteins), an increase of eosinophils above 400/µl 

should be seen as indicating the presence of parasitosis, allergies, and 

many other conditions (p. 124). 

Basophilic Granulocytes (Basophils) 

Like eosinophils, basophils (basophilic granulocytes) mature in parallel 

with cells of the neutrophil lineage. The earliest stage at which they can be 

identified is the promyelocyte stage, at which large, black–violet stained 

granules are visible. In mature basophils, which are relatively small, these 

granules often overlie the two compact nuclear segments like blackberries. 

However, they easily dissolve in water, leaving behind faintly pink 

stained vacuoles. 

Close relations of basophilic granulocytes are tissue basophils or tissue 

mast cells—but these are never found in blood. Tissue basophils have a 

round nucleus underneath large basophilic granules. 

Diagnostic Implications. In line with their role in anaphylactic reactions 

(p. 5), elevated basophil counts are seen above all in hypersensitivity reactions 

of various kinds. Basophils are also increased in chronic myeloproliferative 

bone marrow diseases, especially chronic myeloid leukemia 

(pp. 117, 120). 



a 

c 

e 

Round granules filling the cytoplasm: eosinophilic and basophilic 

granulocytes 

Fig. 14 Eosinophilic and basophilic granulocytes. a–c Eosinophilic granulocytes 

with corpuscular, orange-stained granules. d In contrast, the granules of neutrophilic 

granulocytes are not round but more bud-shaped. e Basophilic granulocyte. 

The granules are corpuscular like those of the eosinophilic granulocyte but stain 

deep blue to violet. f Very prominent large granules in a basophilic granulocyte in 

chronic myeloproliferative disease. 



45 

b 

d 

f

46 

Monocytes 


Monocytes are produced in the bone marrow; their line of development 

branches off at a very early stage from that of the granulocytic series (see 

flow chart p. 3), but does not contain any distinct, specific precursors that 

can be securely identified with diagnostic significance in everyday morphological 

studies. Owing to their great motility and adhesiveness, mature 

monocytes are morphologically probably the most diversified of all 

cells. Measuring anywhere between 20 and 40 µm in size, their constant 

characteristic is an ovoid nucleus, usually irregular in outline, with invaginations 

and often pseudopodia-like cytoplasmic processes. The fine, 

“busy” structure of their nuclear chromatin allows them to be distinguished 

from myelocytes, whose chromatin has a patchy, streaky structure, 

and also from lymphocytes, which have dense, homogeneous nuclei. 

The basophilic cytoplasmic layer varies in width, stains a grayish color, 

and contains a scattered population of very fine reddish granules that are 

at the very limit of the eye’s resolution. These characteristics vary greatly 

with the size of the monocyte, which in turn is dependent on the thickness 

of the smear. Where the smear is thin, especially at the feathered end, 

monocytes are abundant, relatively large and loosely structured, and their 

cytoplasm stains light gray–blue (“dove gray”). In thick, dense parts of the 

smear, some monocytes look more like lymphocytes: only a certain nuclear 

indentation and the “thundercloud” gray–blue staining of the cytoplasm 

may still mark them out. 

Diagnostic Implications. In line with their function (see p. 5) as phagocytic 

defense cells, an elevation of the monocyte population above 7% and 

above 850/µl indicates an immune defense reaction; only when a sharp 

rise in monocyte counts is accompanied by a drop in absolute counts in 

the other cell series is monocytic leukemia suggested (p. 101). Phagocytosis 

of erythrocytes and white blood cells (hemophagocytosis) may occur 

in some virus infections and autoimmune diseases. 

➤ Monocytosis in cases of infection: always present at the end of acute infections; 

chronic especially in 

– Endocarditis lenta, listeriosis, brucellosis, tuberculosis 

➤ Monocytosis in cases of a non-infectious response, e.g., 

– Collagenosis, Crohn disease, ulcerative colitis 

➤ Monocytoses in/as neoplasia, e.g., 

– Paraneoplastic in cases of disseminating tumors, bronchial carcinoma, 

breast carcinoma, Hodgkin disease, myelodysplasias (especially 

CMML, pp. 107 f) and acute monocytic leukemia (p. 101) 



Monocytes show the greatest morphological variation among 

blood cells 

a b 

c d 

e f 

g h 

Fig. 15 Monocytes. a–c Range of appearances of typical monocytes with lobed, 

nucleus, gray–blue stained cytoplasm and fine granulation. d Phagocytic monocyte 

with plasma vacuoles. e Monocyte (1) to the right of a lymphocyte with azurophilic 

granules (2). f Monocyte (1) with nucleus resembling that of a band neutrophil, 

but its cytoplasm stains typically gray–blue. Lymphocyte (2). g A monocyte 

that has phagocytosed two erythrocytes and harbors them in its wide cytoplasm 

(arrows) (sample taken after bone marrow transplantation). h Esterase 

staining, a typical marker enzyme for cells of the monocyte lineage. 

47 



48 


Lymphocytes (and Plasma Cells) 

Lymphocytes are produced everywhere, particularly in the lymph nodes, 

spleen, bone marrow, and the lymphatic islands of the intestinal mucosa, 

under the influence of the thymus (T-lymphocytes, about 80%), or the 

bone marrow (B-lymphocytes, about 20%). A small fraction of the lymphocytes 

are NK cells (natural killer cells). Immature precursor cells (lymph 

node cytology, p. 177) are practically never released into the blood and are 

therefore of no practical diagnostic significance. The cells encountered in 

circulating blood are mostly “small” lymphocytes with oval or round nuclei 

6–9 µm in diameter. Their chromatin may be described as dense and 

coarse. Detailed analysis under the microscope, using the micrometer 

screw to view the chromatin in different planes, reveals not the patch-like 

or banded structure of myeloblast chromatin, or the “busy” structure of 

monocyte chromatin, but slate-like formations with homogeneous chromatin 

and intermittent narrow, lighter layers that resemble geological 

break lines. Nucleoli are rarely seen. The cytoplasm wraps quite closely 

around the nucleus and is slightly basophilic. Only a few lymphocytes display 

the violet stained stippling of granules; about 5% of small lymphocytes 

and about 3% of large ones. The family of large lymphocytes with 

granulation consists mostly of NK cells. An important point is that small 

lymphocytes—which cannot be identified as T- or B-lymphocytes on the 

basis of morphology—are not functional end forms, but undergo transformation 

in response to specific immunological stimuli. The final stage of Blymphocyte 

maturation (in bone marrow and lymph nodes) is plasma 

cells, whose nuclei often show radial bars, and whose basophilic cytoplasm 

layer is always wide. Intermediate forms (“plasmacytoid” lymphocytes) 

also exist. 

Diagnostic Implications. Values between 1500 and 4000/µl and about 35% 

reflect normal output of the lymphatic system. Elevated absolute lymphocyte 

counts, often along with cell transformation, are observed predominantly 

in viral infections (pp. 67, 69) or in diseases of the lymphatic system 

(p. 75 ff.). Relative increases at the expense of other blood cell series may 

be a manifestation of toxic or aplastic processes (agranulocytosis, p. 87; 

aplastic anemia, p. 148), because these irregularities are rare in the lymphatic 

series. A spontaneous decrease in lymphocyte counts is normally 

seen only in very rare congenital diseases (agammaglobulinemia [Bruton 

disease], DiGeorge disease [chromosome 22q11 deletion syndrome]). 

Some systemic diseases also lead to low lymphocyte counts (Hodgkin disease, 

active AIDS). 

Mature plasma cells are rarely found in blood (plasma cell leukemia is 

extremely rare). Plasma-cell-like (“plasmacytoid”) lymphocytes occur in 

viral infections or systemic diseases (see p. 68 f. and p. 74 f.). 



a 

b c 

d 

Lymphocytes are small round cells with dense nuclei and some 

variation in their appearance 

f 

g 

Fig. 16 Lymphocytes a–c Range of appearance of normal lymphocytes (some of 

them adjacent to segmented neutrophilic granulocytes). d In neonates, some 

lymphocytes from a neonate show irregularly shaped nuclei with notches or hints 

of segmentation. e A few larger lymphocytes with granules may occur in a normal 

person. f Occasionally, and without any recognizable trigger, the cytoplasm may 

widen. g A smear taken after infection may contain a few plasma cells, the final, 

morphologically fully developed cells in the B-lymphocyte series (for further activated 

lymphocyte forms, see p. 67). 

49 



e

50 


Megakaryocytes and Thrombocytes 

Megakaryocytes can enter the bloodstream only in highly pathological 

myeloproliferative disease or acute leukemia. They are shown here in 

order to demonstrate thrombocyte differentiation. Megakaryocytes reside 

in the bone marrow and have giant, extremely hyperploid nuclei (16 

times the normal number of chromosome sets on average), which build up 

by endomitosis. Humoral factors regulate the increase of megakaryocytes 

and the release of thrombocytes when more are needed (e.g., bleeding or 

increased thrombocyte degradation). Cytoplasm with granules is pinched 

off from megakaryocytes to form thrombocytes. The residual naked megakaryocyte 

nuclei are phagocytosed. 

Only mature thrombocytes occur in blood. About 1–4 µm in size and 

anuclear, their light blue stained cytoplasm and its processes give them a 

star-like appearance, with fine reddish blue granules near the center. 

Young thrombocytes are larger and more “spread out;” older ones look 

like pyknotic dots. 

Diagnostic Implications. In a blood smear, there are normally 8–15 thrombocytes 

per view field using a 100 objective; they may appear dispersed 

or in groups. To someone quickly screening a smear, they will give a good 

indication of any increase or strong decrease in the count, which can be 

useful for early diagnosis of acute thrombocytopenias (p. 164 f.). 

Small megakaryocyte nuclei are found in the bloodstream only in 

severe myeloproliferative disorders (p. 171). 



Megakaryocytes are never present in a normal peripheral blood 

smear. Thrombocytes are seen in every field view 

a b 

c d 

Fig. 17 Megakaryocytes and thrombocytes. a Megakaryocytes in a bone marrow 

smear. The wide cytoplasm displays fine, cloudy granulation as a sign of incipient 

thrombocyte budding. b Normal density of thrombocytes among the erythrocytes, 

with little variation in thrombocyte size. c and d Peripheral blood smears 

with aggregations of thrombocytes. When such aggregates are seen against a 

background of apparent thrombocytopenia, the phenomenon is called “pseudothrombocytopenia” 

and is usually an effect of the anticoagulant EDTA (see also 

p. 167). 

51 



52 


Bone Marrow: Cell Composition 

and Principles of Analysis 

As indicated above, and as will be shown below, almost all disorders of the 

hematopoietic system can be diagnosed using clinical findings, blood 

analysis, and humoral data. There is no mystery about bone marrow diagnostics. 

The basic categories are summarized here to give an understanding 

of how specific diagnostic information is achieved; photomicrographs 

will show the appearance of specific diseases. Once the individual cell 

types, as given in the preceding pages, are recognized, it becomes possible 

to interpret the bone marrow smears that accompany the various diseases, 

and to follow further, analogous diagnostic steps. As a first step in 

the analysis of a bone marrow tissue smear or squash preparation, various 

areas in several preparations are broadly surveyed. This is followed by individual 

analysis of at least 200 cells from two representative areas. Table 

4 shows the mean normal values and their wide ranges. 

A combination of estimation and quantitative analysis is used, based on 

the following criteria: 

Cell Density. This parameter is very susceptible to artifacts. Figure 18 

shows roughly the normal cell density. A lower count may be due to the 

manner in which the sample was obtained or to the smearing procedure. A 

bone marrow smear typically shows areas where connective tissue adipocytes 

with large vacuoles predominate. Only if these adipocytes areas are 

present is it safe to assume that the smear contains bone marrow material 

and that an apparent deficit of bone marrow cells is real. 

Increased cell density: e.g., in all strong regeneration or compensation 

processes, and in cases of leukemia and myeloproliferative syndromes 

(except osteomyelosclerosis). 

Decreased cell density: e.g., in aplastic processes and myelofibrosis. 



Bone Marrow: Cell Composition and Principles of Analysis 

Table 4 Cell composition in the bone marrow: normal values (%) 

Median 

values 

(J. Boll) 

Median values and normal 

range 

(K. Rohr) 

Red cell series 

– Proerythrocytes 1 

– Macroblasts (basophilic 

erythroblasts) 

3 3.5 0.5–7.5 

– Normoblasts (poly- and 

orthochromic erythroblasts) 

16 19 (7–40) 

Neutrophil series 

– Myeloblasts 2.7 1 (0.5–5) 

– Promyelocytes 9.5 3 (0–7.5) 

– Myelocytes 14 15 (5–25) 

– Metamyelocytes 10.5 15 (5–20) 

– Band neutrophils 9.8 15 (5–25) 

– Segmented neutrophils 17.5 7 (0.5–15) 

Small cell series 

– Eosinophilic granulocytes 5 3 (1–7) 

– Basophilic granulocytes 1 0.5 (0–1) 

– Monocytes 2 2 (0.5–3) 

– Lymphocytes 6 7.5 (2.5–15) 

– Plasma cells 1.5 1 (0.5–3) 


Cell densities vary widely, 0.5–2 per view field during screening at low magnification. 

53 

Ratios of Red Cell Series to White Cell Series. In the final analysis, bone 

marrow cytology allows a quantitative assessment only in relative terms. 

The important ratio of red precursor cells to white cells is 1 : 2 for men 

and 1 : 3 for women. 

Shifts towards erythropoiesis are seen in all regenerative anemias (hemorrhagic 

anemia, iron deficiency anemia, vitamin deficiency anemia, and 

hemolysis), pseudopolycythemia (Gaisböck syndrome), and polycythemia, 

also in rare pseudo-regenerative disorders, such as sideroachrestic 

anemia and myelodysplasias. Shifts toward granulopoiesis are seen 

in all reactive processes (infections, tumor defense) and in all malignant 

processes of the white cell series (chronic myeloid leukemia, acute 

leukoses). 



54 


Distribution and Cell Quality in Erythropoiesis. In erythropoiesis polychromatic 

erythroblasts normally predominate. Proerythroblasts and basophilic 

erythroblasts only make up a small portion (Table 4). Here, too, a 

left shift indicates an increase in immature cell types and a right shift an 

increase in orthochromatic erythroblasts. Qualitatively, vitamin B12 and 

folic acid deficiency lead to a typical loosening-up of the nuclear structure 

in proerythroblasts and to nuclear segmentation and break-up in the 

erythroblasts (megaloblastic erythropoiesis). 

A left shift is seen in regenerative anemias except hemolysis. Atypical 

proerythroblasts predominate in megaloblastic anemia and erythremia. 

A right shift is seen in hemolytic conditions (nests of normoblasts, erythrons). 

Distribution and Cell Quality in Granulopoiesis. The same principle is valid 

as for erythropoiesis: the more mature the cells, the greater proportion of 

the series they make up. A left shift indicates a greater than normal proportion 

of immature cells and a right shift a greater than normal proportion 

of mature cells (Table 4). Strong reactive conditions may lead to dissociations 

in the maturation process, e.g., the nucleus shows the structure of 

a myelocyte while the cytoplasm is still strongly basophilic. In malignancies, 

the picture is dominated by blasts, which may often be difficult to 

identify with any certainty. 

A left shift is observed in all reactive processes and at the start of neoplastic 

transformation (smoldering anemia, refractory anemia with 

excess blasts [RAEB]). In acute leukemias, undifferentiated and partially 

matured blasts may predominate. In agranulocytosis, promyelocytes are 

most abundant. 

A right shift is diagnostically irrelevant. 

Cytochemistry. To distinguish between reactive processes and chronic 

myeloid leukemia, leukocyte alkaline phosphatase is determined in fresh 

smears of blood. To distinguish between different types of acute leukemia, 

the peroxidase and esterase reactions are carried out (pp. 97 and 99), and 

iron staining is performed (p. 109) if myelodysplasia is suspected. 

Cytogenetic Analysis. This procedure will take the diagnosis forward in 

cases of leukemia and some lymphadenomas. The fresh material must be 

heparinized before shipment, preferably after discussion with a specialist 

laboratory. 



a b 

c 

The bone marrow contains a mixture of all the hematopoietic 

cells 

Fig. 18 Bone marrow cytology. a Bone marrow cytology of normal cell density in 

a young adult (smear from a bone marrow spicule shown at the lower right; magnification 

100). b More adipocytes with large vacuoles are present in this bone 

marrow preparation with normal hematopoietic cell densities; usually found in 

older patients. c Normal bone marrow cytology (magnification 400). Even this 

overview shows clearly that erythropoiesis (dense, black, round nuclei) accounts 

for only about one-third of all the cells. 



55

56 


Qualitative and Quantitative Assessment of the Remaining Cells. Lymphocyte 

counts may be slightly raised in reactive processes, but a significant 

increase suggests a disease of the lymphatic system. The exact classification 

of these disease follows the criteria of lymphocyte morphology 

(Fig. 16). If elevated lymphocyte counts are found only in one preparation 

or within a circumscribed area, physiological lymph follicles in the bone 

marrow are likely to be the source. In a borderline case, the histology and 

analysis of lymphocyte surface markers yield more definitive data. 

Plasma cell counts are also slightly elevated in reactive processes and 

very elevated in plasmacytoma. Reactive increase of lymphocytes and 

plasma cells with concomitant low counts in the other series is often an 

indication of panmyelopathy (aplastic anemia). 

Raised eosinophil and monocyte counts in bone marrow have the same 

diagnostic significance as in blood (p. 44). 

Megakaryocyte counts are reduced under the effects of all toxic stimuli 

on bone marrow. Counts increase after bleeding, in essential thrombocytopenia 

(Werlhof syndrome), and in myeloproliferative diseases (chronic 

myeloid leukemia, polycythemia, and essential thrombocythemia). 

Iron Staining of Erythropoietic Cells. Perls’ Prussian blue (also known as 

Perls’ acid ferrocyanide reaction) shows the presence of ferritin in 20–40% 

of all normoblasts, in the form of one to four small granules. The ironcontaining 

cells are called sideroblasts. Greater numbers of ferritin 

granules in normoblasts indicate a disorder of iron utilization (sideroachresia, 

especially in myelodysplasia), particularly when the granules 

form a ring around the nucleus (ring sideroblasts). Perls’ Prussian blue reaction 

also stains the diffuse iron precipitates in macrophages (Fig. 19 b). 

Under exogenous iron deficiency conditions the proportion of sideroblasts 

and iron-storing macrophages is reduced. However, if the shift in 

iron utilization is due to infectious and/or toxic conditions, the iron content 

in normoblasts is reduced while the macrophages are loaded with 

iron to the point of saturation. In hemolytic conditions, the iron content of 

normoblasts is normal; it is elevated only in essential or symptomatic refractory 

anemia (including megaloblastic anemia). 



Not just the individual cell, but its relative proportion is relevant 

in bone marrow diagnostics 

a b 

c d 

Fig. 19 Normal bone marrow findings. a Normal bone marrow: megakaryocyte 

(1), erythroblasts (2), and myelocyte (3). b Iron staining in the bone marrow cytology: 

iron-storing macrophage. c Normal bone marrow with slight preponderance 

of granulocytopoiesis, e.g., promyelocyte (1), myelocyte (2), metamyelocyte (3), 

and band granulocyte (4). d Normal bone marrow with slight preponderance of 

erythropoiesis, e.g., basophilic erythroblast (1), polychromatic erythroblasts (2), 

and orthochromatic erythroblast (3). Compare (differential diagnosis) with the 

plasma cell (4) with its eccentric nucleus. 

57 



58 


Bone Marrow: Medullary Stroma Cells 

➤ Fibroblastic reticular cells form a firm but elastic matrix in which the 

blood-forming cells reside, and are therefore rarely found in the bone 

marrow aspirate or cytological smear. When present, they are most 

likely to appear as dense cell groups with long fiber-forming cytoplasmic 

processes and small nuclei. Iron staining shows them up as a 

group of reticular cells which, like macrophages, have the potential to 

store iron. If they become the prominent cell population in the bone 

marrow, an aplastic or toxic medullary disorder must be considered. 

➤ Reticular histiocytes (not yet active in phagocytosis) are identical to 

phagocytic macrophages and are the main storage cells for tissuebound 

iron. Because of their small nuclei and easy-flowing cytoplasm, 

they are noticeable after panoptic staining only when they contain obvious 

entities such as lipids or pigments. 

➤ Osteoblasts are large cells with wide, eccentric nuclei. They differ from 

plasma cells in that the cytoplasm has no perinuclear lighter space (cell 

center) and stains a cloudy grayish-blue. As they are normally rare in 

bone marrow, increased presence of osteoblasts in the marrow may indicate 

metastasizing tumor cells (from another location). 

➤ Osteoclasts are multinucleated syncytia with wide layers of grayishblue 

stained cytoplasm, which often displays delicate azurophilic 

granulation. They are normally extremely rare in aspirates, and when 

they are found it is usually under the same conditions as osteoblasts. 

They are distinguished from megakaryocytes by their round and regular 

nuclei and by their lack of thrombocyte buds. 

From the above, it will be seen that bone marrow findings can be assessed 

on the basis of a knowledge of the cells elements described above 

(p. 32 ff.), taking account of the eight categories given on p. 52 f. It also 

shows that a diagnosis from bone marrow aspirates can safely be made 

only in conjunction with clinical findings, blood chemistry, and the qualitative 

and quantitative blood values. For this reason, a table of diagnostic 

steps taking account of these categories is provided at the beginning of 

each of the following chapters. 



a 

c 

Cells from the bone marrow stroma never occur in the blood 

stream 

Fig. 20 Bone marrow stroma. a Spindle-shaped fibroblasts form the structural 

framework of the bone marrow (shown here: aplastic hematopoiesis after therapy 

for multiple myeloma). b A macrophage has phagocytosed residual nuclear 

material (here after chemotherapy for acute leukemia). c Bone marrow osteoblasts 

are rarely found in the cytological assessment. The features that distinguish 

osteoblasts from plasma cells are their more loosely structured nuclei and the 

cloudy, “busy” basophilic cytoplasm. d Osteoclasts are multinucleated giant cells 

with wide, spreading cytoplasm. 

59 



b 

d

60 



Abnormalities of the White Cell Series 



62 


A very old-fashioned, intuitive way of classifying CBCs is to divide them 

into those in which round to oval (mononuclear) cells predominate and 

those in which segmented (polynuclear) cells predominate. However, this 

old method does allow the relevant differential diagnosis to be inferred 

from a cursory screening of a slide. 

Differential Diagnostic Notes 

Differential diagnosis when round to oval cells predominate 

➤ Reactive lymphocytoses and monocytoses, pp. 67 f., 89 

➤ Lymphatic system diseases (lymphomas, lymphocytic leukemia), 

p. 70 

➤ Acute leukemias, including episodes of chronic myeloid leukemia 

(CML), p. 96 ff. 

➤ Low counts of cells with segmented nuclei (agranulocytosis– 

aplastic anemia–myelodysplasia), pp. 86, 106, 148 

Differential diagnosis when segmented cells predominate 

➤ Reactive processes, p. 112 ff. 

➤ Chronic myeloid leukemia, p. 114 ff. 

➤ Osteomyelosclerosis, p. 122 

➤ Polycythemia vera, p. 162 ff. 



Predominance of Mononuclear Round to Oval Cells 

Predominance of Mononuclear Round 

to Oval Cells (Table 5) 

63 

The cell counts (per microliter) show a wide range of values and depend 

on a variety of conditions even in normal blood. Any disease may therefore 

result in higher (leukocytosis) or lower cell counts (leukopenia). The 

assessment of cell counts requires the knowledge of normal values and 

their ranges (spreads) (Table 2, p. 12). The most important diagnostic indicator 

therefore is not the cell count but the cell type. In a first assessment, 

mononuclear (round to oval) and polynuclear (segmented) cells are 

compared. This is the first step in the differential diagnosis of the multifaceted 

spectrum of blood cells. 

Absolute or relative predominance of mononuclear cells points to a defined 

set of diagnostic probabilities. The differential diagnostic notes opposite 

can help with a first orientation. 

Consequently, the most important step is to distinguish between lymphatic 

cells and myeloid blasts. The nuclear morphology makes it possible 

to distinguish between the two cell types. In lymphatic cells the nucleus 

usually displays dense coarse chromatin with slate-like architecture and 

lighter zones between very dense ones. In contrast, the immature cells in 

myeloid leukemias contain nuclei with a more delicate reticular, sometimes 

sand-like chromatin structure with a finer, more irregular pattern. 



64 

Table 5 Diagnostic work-up for abnormalities in the white cell series with mononuclear 

cells predominating 

Clinical findings Hb MCH Leukocytes Segmented 

cells 

Fever, lymph nodes, 

possibly exanthema 

Fever, severe lymphoma, 

possibly 

spleen ↑ 

Slowly progressing 

lymph node enlargement 

in several locations 

Night sweat, slowly 

progressing lymphoma 

(spleen), 

possibly fever 

Slowly progressing 

lymph node enlargement 

in one or a few 

locations 

Isolated severe 

splenomegaly 

Lymphocytes 

(%) 

n n ↓/n ↓ ↑ 

Stimulated 

forms 

Other cells 

n n ↑ ↓ ↑ Large blastic 

stimulated cells 

(DD: lymphoblasts) 

↓/n ↓/n ↑ ↓ ↑↑ – 

↓ ↓ n/↑ ↓ ↑ Plasmacytoid 

cells, possibly 

rouleaux formation 

of the 

erythrocytes 

↓ n/↓ n/↑/↓ n/↓ Possibly ↑ Possibly cells 

with grooves 

↓ ↓ ↓/↑ ↓ Hairy cells 

Fever, angina n n ↓ ↓ ↑ Monocytes ↑ 

Diffuse general 

symptoms 

Pale skin, fever 

(signs of hemorrhage) 

Fatigue, night 

sweat, possibly 

bone pain 


↓ ↓ ↑ ↓ n Monocytes ↑ 

↓ ↓ ↑/n/↓ ↓ ↓ Atypical round 

cells predominate 

↓ ↓ n/↓ n n Possibly rouleaux 

formations of 

erythrocytes 

Diagnostic steps proceed from left to right. | The next step is usually unnecessary; optional 

step, may not progress the diagnosis; ⎯→ the next step is obligatory. 



–

Thrombocytes 

Electrophoresis 

Tentative 

diagnosis 

n n/Y↑ Virus infection, 

e.g., rubeola 

n Y↑ Mononucleosis 

n/↓ n/Y↓ Leukemic 

non-Hodgkin 

lymphoma, 

esp. CLL 

n/↓ Possibly 

Y↑ 

Immunocytoma 

(incl. 

Waldenströmdisease) 

n/↓ n Non-Hodgkin 

lymphoma, 

e.g. follicular 

lymphoma 

↓ n Hairy cell 

leukemia 

n n Agranulocytosis 

n Possibly 

a2↑ 

Reactive 

monocytosis 

in chronic 

infection or 

tumor 

↓ n Acute 

leukemia 

n/↓ Sharp 

peaks ↑ 


Multiple 

myeloma 

Evidence/advanced 

diagnostics 

Clinical developments, 

possibly serological 

tests 

Mononucleosis quick 

test, EBV serology 

(cytomegaly titer?) 

Marker analysis of 

peripheral lymphocytes 

is sufficient in typical 

disease presentations; 

lymph node histology 

for treatment decisions, 

if necessary 

Immunoelectrophoresis; 

marker analysis for 

lymphocytes in blood 

and bone marrow; 

lymph node histology in 

case of doubt 

Lymph node histology 

Cell surface markers 

. 

Bone marrow 

Always 

involved in 

CLL, not 

always in 

other lymphomas 

Usually 

involved 

Ref. page 

p. 66 

p. 68 

p. 74 

p. 78 

. 

For the pur- p. 78 

pose of staging, 

possibly 

positive 

. 

Always p. 80 

involved, discrete 

in the 

beginning 

. 

⎯⎯⎯⎯⎯⎯⎯⎯→ Maturation 

arrest 

Determine disease 

origin 

Cytochemistry, marker 

analysis, possibly cytogenetics 

⎯⎯⎯⎯⎯⎯⎯⎯→ 

Immunoelectrophoresis, 

skeletal X-ray 

⎯⎯⎯⎯⎯⎯⎯⎯→ 

Marker for 

blasts 

Bone marrow 

contains 

plasma cells 



p. 86 

p. 88 

p. 90ff 

p. 82 

65

66 


Reactive Lymphocytosis 

Lymphatic cells show wide variability and transform easily. This is usually 

seen as enlarged nuclei, a moderately loose, coarse chromatin structure, 

and a marked widening of the basophilic cytoplasmic layer. 

Clinical findings, which include acute fever symptoms, enlarged lymph 

nodes, and sometimes exanthema, help to identify a lymphatic reactive 

state. Unlike the case in acute leukemias, erythrocyte and thrombocyte 

counts are not significantly reduced. Although the granulocyte count is 

relatively reduced, its absolute value (per microliter) rarely falls below the 

lower limit of normal values. 

Morphologically normal lymphocytes predominate in the blood analyses in 

the following diseases: 

➤ Whooping cough (pertussis) with clear leukocytosis and total lymphocyte 

counts up to 20 000 and even 50 000/µl; occasionally, slightly 

plasmacytoid differentiation. 

➤ Infectious lymphocytosis, a pediatric infectious disease with fever of 

short duration. Lymphocyte counts may increase to 50 000/µl. 

➤ Chickenpox, measles, and brucellosis, in which a less well-developed 

relative lymphocytosis is found, and the counts remain within the normal 

range. 

➤ Hyperthyroidism and Addison disease, which show relative lymphocytosis. 

➤ Constitutional relative lymphocytosis, which can reach up to 60% and 

occurs without apparent reason (mostly in asthenic teenagers). 

➤ Absolute granulocytopenias with relative lymphocytosis (p. 86). 

➤ Chronic lymphocytic leukemia (CLL), which is always accompanied by 

absolute and relative lymphocytosis, usually with high cell counts. 

Transformed, “stimulated” lymphocytes (“virocytes”) predominate in the 

CBC in the following diseases with reactive symptoms: 

➤ Lymphomatous toxoplasmosis does not usually involve significant 

leukocytosis. Slightly plasmacytoid cell forms are found. 

➤ In rubella infections the total leukocyte count is normal or low, and the 

lymphocytosis is only relatively developed. The cell morphology ranges 

from basophilic plasmacytoid cells to typical plasma cells. 

➤ In hepatitis the total leukocyte and lymphocyte counts are normal. 

However, the lymphocytes often clearly show plasmacytoid transformation. 

➤ The most extreme lymphocyte transformation is observed in mononucleosis 

(Epstein–Barr virus [EBV] or cytomegalovirus [CMV] infection) 

(p. 68). 



a 

b 

d 

During lymphatic reactive states, variable cells with dense, 

round nuclei (e.g., virocytes) dominate the CBC 

Fig. 21 Lymphatic reactive states. a–e Wide variability of the lymphatic cells in a 

lymphotropic infection (in this case cytomegalovirus infection). Some of the cells 

may resemble myelocytes, but their chromatin is always denser than myelocyte 

chromatin. 



67 

c 

e

68 


Examples of Extreme Lymphocytic Stimulation: 

Infectious Mononucleosis 

Epstein–Barr virus infection should be considered when, after a prodromal 

fever of unknown origin, there are signs of enlarged lymph nodes and 

developing angina, and the blood analysis shows predominantly mononuclear 

cells and a slightly, or moderately, elevated leukocyte count. Varying 

proportions of the mononuclear cells (at least 20%) may be rather extensively 

transformed round cells (Pfeiffer cells, virocytes). Immunological 

markers are necessary to ascertain that these are stimulated lymphocytes 

(mostly T-lymphocytes) defending the B-lymphocyte stem population 

against the virus attack. The nuclei of these stimulated lymphocytes are 

two- to three-fold larger than those of normal lymphocytes and their 

chromatin has changed from a dense and coarse structure to a looser, 

more irregular organization. The cytoplasm is always relatively wide and 

more or less basophilic with vacuoles. Granules are absent. A small proportion 

of cells appear plasmacytoid. In the course of the disease, the 

degree of transformation and the proportions of the different cell morphologies 

change almost daily. A slight left shift and elevated monocyte 

count are often found in the granulocyte series. 

Acute leukemia is often considered in the differential diagnosis in addition 

to other viral conditions, because the transformed lymphocytes can 

resemble the blasts found in leukemia. Absence of a quantitative reduction 

of hematopoiesis in all the blood cell series, however, makes leukemia 

unlikely, as do the variety and speed of change in the cell morphology. Finally, 

serological tests (EBV antigen test, test for antibodies, and, if indicated, 

quick tests) can add clarification. 

Where serological tests are negative, the cause of the symptoms is usually 

cytomegalovirus rather than EBV. 

Characteristics of Infectious Mononucleosis 

Age of onset: School age 

Clinical findings: Enlarged lymph nodes (rapid onset), inflammations 

of throat and possibly spleen 

CBC: Leukocytes , stimulated lymph nodes, partially lymphoblasts 

(hematocrit and thrombocytes are normal) 

Further diagnostics: EBV serological test (IgM +), transaminases usually 

 

Differential diagnosis: Lymphomas (usually without fever), leukemia 

(usually Hb , thrombocytes ) Persistent disease (more than 3 

weeks): possibly test for blood cell markers, lymph node cytology 

( histology) 

Course, treatment: Spontaneous recovery within 2–4 weeks; general 

palliation 



a 

Extreme transformation of lymphocytes leads to blast-like cells: 

mononucleosis 

c 

d 

Fig. 22 Lymphocytes during viral infection. a “Blastic,” lymphatic reactive form 

(Pfeiffer cell), in addition to less reactive virocytes in Epstein–Barr virus (EBV) infection. 

This phase with blastic cells lasts only a few days. b Virocyte (1) with homogeneous 

deep blue stained cytoplasm in EBV infection, in addition to normal 

lymphocyte (2) and monocyte (3). c Virus infection can also lead to elevated 

counts of large granulated lymphocytes (LGL) (1). Monocyte (2). d Severe 

lymphatic stress reaction with granulated lymphocytes. A lymphoma must be 

considered if this finding persists. 

69 



b

70 


Diseases of the Lymphatic System 

(Non-Hodgkin Lymphomas) 

Malignant diseases of the lymphatic system are further classified as Hodgkin 

and non-Hodgkin lymphomas (NHL). NHL will be discussed here because 

most NHLs can be diagnosed on the blood analysis. 

➤ Non-Hodgkin lymphomas arise mostly from small or blastic B-cells. 

➤ Small-cell NHL cells are usually leukemic and relatively indolent, of the 

type of chronic lymphocytic leukemia and its variants. 

➤ Blastic NHL (precursor lymphoma) is not usually leukemic. An exception 

is the lymphoblastic lymphoma, which takes its course as an acute 

lymphocytic leukemia. 

➤ Plasmacytoma is an osteotropic B-cell lymphoma that releases not its 

cells but their products (immunoglobulins) into the bloodstream. 

➤ Malignant lymphogranulomatosis (Hodgkin disease) cannot be diagnosed 

on the basis of blood analysis. It is therefore discussed under 

lymph node cytology (p. 176). 

The modern pathological classification of lymphomas is based on morphology 

and cell immunology. The updated classification system according 

to Lennert (Kiel) has been adopted in Germany and was recently modified 

to reflect the WHO classification. The definitions of stages I–IV in NHL 

agree with the Ann Arbor classification for Hodgkin’s disease. 

Table 6a Classification of non-Hodgkin: comparison of the relevant classes in the Kiel and WHO classifications 

WHO Kiel Clinical 

Characteristics 

Precursor lymphomas/leukemias 

➤ Precursor-B-lymphoblastic 

lymphoma 

➤ Precursor B-cell active lymphoblastic 

leukemia 

Mature B-cell lymphoma 

➤ Chronic lymphocytic leukemia 

– contains the lymphoplasmacytoid 

immunocytoma 

B-lymphoblastic 

lymphoma 

B-ALL 

B-CLL 

Lymphoplasmacytoid 

immunocytoma 

Marker* 

Aggressive Tdt, 

CD19, 22, 

79 a 

Usually indolent 


➤ B-cell prolymphocytic leukemia Aggressive 



CD5, 19, 

20, 23 

tris 12 or 

13 q-, 

11 q-, 6 q-, 

p 53

Table 6a Continued 

WHO Kiel Clinical 


➤ Lymphoplasmacytic leukemia Lymphoplasmacytic 

immunocytoma 

Sometimes IgM 

paraprotein 

(Waldenström 

disease) 

➤ Mantle cell lymphoma Centrocytic lymphoma Usually aggressive 

➤ Marginal zone lymphoma 

– Nodal 

– Extranodal in mucosa (MALT) 

– Lienal (splenic) 

➤ Follicular lymphoma 

– Grade 1, 2 

– Grade 3 (a, b) 

Monocytoid lymphoma 

MALT (mucosa-assoc. 

lymphoid tissue) lymphoma 

Lymphoma with 

splenomegaly 

Centroblastic/centrocytic 

lymphoma; 

centroblastic lymphoma 

(a), secondary (b), follicular 

Usually aggressive 

Often indolent 


Highly malignant 

Marker* 

–/+ CD5 

– CD23, 

CD5 

t(11;14) 

bcl-1 

rearr. 

–CD5, 

CD23 

–CD5, 

CD10 

t(14;18) 

bcl2 

➤ Hairy cell leukemia Hairy cell leukemia Usually indolent –CD103, 

CD11 c, 

CD25 

t(2;8) 

t(8;14) 

➤ Plasma cell myeloma (plasmacytoma) 

– Monoclonal hypergammaglobulinemia 

(GUS) 

– Solitary bone plasmacytoma 

– Extraosseous bone plasmacytoma 

– Primary amyloidosis 

– Heavy-chain disease 

Primary large-cell lymphoma 

➤ Diffuse large-cell B-cell 

lymphoma 

– Centroblastic 

– Immunoblastic 

– Large-cell anaplastic 


[Plasmacytoma is not 

included in the Kiel 

classification] 

Centroblastic 

Immunoblastic 

Large-cell anaplastic 

Extremely malignant 



➤ Burkitt lymphoma Burkitt lymphoma Extremely malignant 

* Cited markers are positive, absent markers are indicated with a minus sign. 



CD 138 

CD20, 

79 a, 19, 

22 

t(2;8) 

t(8;14) 

myc 

71

72 

Table 6b T-cell lymphomas (since T-cell lymphomas make up only 10% of all NHLs, this table gives just a brief 

characterization; for markers see Table 7) 

WHO 

( Kiel) 


Classification Manifestation 

➤ T-prolymphocytic leukemia 

➤ Large granular lymphocyte leukemia (LGL) 

➤ T-cell lymphoblastic leukemia 

Leukemic 

Leukemic 

Leukemic 

Clinical characteristics 

Aggressive 

Sometimes indolent 

Aggressive 

➤ Sézary syndrome, mycosis fungoides Cutaneous Chronic, progressive 

➤ Angioimmunoblastic T-cell lymphoma (AILD) Nodal and ENT Usually aggressive 

➤ Lymphoblastic T-cell lymphoma 

➤ T-cell zone lymphoma (nonspecific peripheral 

lymphoma) 

➤ Lennert lymphoma with multifocal epithelioid 

cells 

➤ Large-cell anaplastic lymphoma (ki1) 

Nodal 

Nodal 

Nodal 

Nodal 

Differentiation of the Lymphatic Cells and Cell Surface 

Marker Expression in Non-Hodgkin Lymphoma Cells 

Aggressive 

Sometimes slowly 

progressive 

Sometimes slowly 

progressive 

Aggressive 

Non-Hodgkin lymphoma cells derive monoclonally from specific stages in 

the B- or T-cell differentiation, and their surface markers reflect this. The 

surface markers are identified in immunocytological tests (Table 7) carried 

out on heparinized blood or bone marrow spicules. 

The blastic lymphomas will not be discussed further in the context of 

diagnostics based on blood cell morphology. The findings in the primarily 

leukemic forms of the disease, such as lymphoblastic lymphoma, resemble 

those for ALL (p. 104). Other blastic lymphomas can usually only 

be diagnosed on the basis of lymph node tissue (Fig. 65). Of course, despite 

all the progress in the analysis of blood cell differentiation, often analysis 

of histological slides in conjunction with the blood analysis is required for 

a confident diagnosis. 



Table 7 Cell surface markers of lymphatic cells in leukemic, low-grade malignant non-Hodgkin lymphoma 

Marker B-CLL B-PLL HCL FL MCL SLVL T-CLL GL SS T-PLL ATLL 


S Ig (+) ++ ++ ++ ++ ++ – – – – – 

CD 2 – – – – – – + + + + + 

CD 3 – – – – – – + – + + + 

CD 4 – – – – – – – – + +/– + 

CD 5 ++ – – – + – – – + + + 

CD 7 – – – – – – – – +/– + –/+ 

CD 8 – – – – – – + +/– +/– +/– +/– 

CD 19/20/24 ++ ++ ++ + + ++ – – – – – 

CD 22 +/– ++ ++ + + ++ – – – – – 

CD 10 – – – +/– – – – – – – – 

CD 25 – – ++ – – +/– – – – – + 

CD 56 – – – – – – – + – – – 

CD 103 – – ++ – – – – – – – – 

CLL chronic lymphocytic leukemia; PLL prolymphocytic leukemia; HCL hairy cell leukemia; FL follicular lymphoma; MCL mantle cell lymphoma; SLVL splenic lymphoma with villous lymphocytes; 

LGL large granular lymphocyte leukemia; SS Sézary syndrome; ATLL adult T-cell lymphoma. 



73

74 


Chronic Lymphocytic Leukemia (CLL) and Related Diseases 

A chronic lymphadenoma, or chronic lymphocytic leukemia, can sometimes 

be clinically diagnosed with some certainty. An example is the case 

of a patient (usually older) with clearly enlarged lymph nodes and significant 

lymphocytosis (in 60% of the cases this is greater than 20 000/µl and 

in 20% of the cases it is greater than 100 000/µl) in the absence of symptoms 

that point to a reactive disorder. The lymphoma cells are relatively 

small, and the nuclear chromatin is coarse and dense. The narrow layer of 

slightly basophilic cytoplasm does not contain granules. Shadows around 

the nucleus are an artifact produced by chromatin fragmentation during 

preparation (Gumprecht’s nuclear shadow). In order to confirm the diagnosis, 

the B-cell markers on circulating lymphocytes should be characterized 

to show that the cells are indeed monoclonal. The transformed 

lymphocytes are dispersed at varying cell densities throughout the bone 

marrow and the lymph nodes. A slowly progressing hypogammaglobulinemia 

is another important indicator of a B-cell maturation disorder. 

Transition to a diffuse large-cell B-lymphoma (Richter syndrome) is 

rare: B-prolymphocytic leukemia (B-PLL) displays unique symptoms. At 

least 55% of the lymphocytes in circulating blood have large central 

vacuoles. When 15–55% of the cells are prolymphocytes, the diagnosis of 

atypical CLL, or transitional CLL/PLL is confirmed. In some CLL-like diseases, 

the layer of cytoplasm is slightly wider. B-CLL was defined as lymphoplasmacytoid 

immunocytoma in the Kiel classification. According to 

the WHO classification, it is a B-CLL variation (compare this with lymphoplasmacytic 

leukemia, p. 78). CLL of the T-lymphocytes is rare. The cells 

show nuclei with either invaginations or well-defined nucleoli (T-prolymphocytic 

leukemia). The leukemic phase of cutaneous T-cell lymphoma 

(CTCL) is known as Sézary syndrome. The cell elements in this syndrome 

and T-PLL are similar. 

Fig. 23 CLL. a Extensive proliferation of lymphocytes with densely structured 

nuclei and little variation in CLL. Nuclear shadows are frequently seen, a sign of 

the fragility of the cells (magnification 400). b Lymphocytes in CLL with typical 

coarse chromatin structure and small cytoplasmic layer (enlargement of a section 

from 23 a, magnification 1000); only discreet nucleoli may occur. c Slightly 

eccentric enlargement of the cytoplasm in the lymphoplasmacytoid variant of 

CLL. 



a 

c 

d 

Monotonous proliferation of small lymphocytes suggests chronic 

lymphocytic leukemia (CLL) 

Fig. 23 d Proliferation of atypical large lymphocytes (1) with irregularly structured 

nucleus, well-defined nucleolus, and wide cytoplasm (atypical CLL or transitional 

form CLL/PLL). e Bone marrow cytology in CLL: There is always strong 

proliferation of the typical small lymphocytes, which are usually spread out diffusely. 



75 

b 

e

76 

Table 8 Staging of CLL according to Rai (1975) 

Stage Identifying criteria/definition 

(Low risk) 0 Lymphocytosis 15 000/µl 

Bone marrow infiltration 40% 

(Intermediate 

risk) 


I 

II 

Lymphocytosis and lymphadenopathy 

Lymphocytosis and hepatomegaly and/or splenomegaly 

(with or without lymphadenopathy) 

(High risk) III Lymphocytosis and anemia (Hb 11.0 g/dl) (with or 

without lymphadenopathy and/or organomegaly) 

IV Lymphocytosis and thrombopenia ( 100 000/µl) 

(with or without anemia, lymphadenopathy, or 

organomegaly) 

Table 9 Staging of CLL according to Binet (1981) 

Stage Identifying criteria/definition 

A Hb 10.0 g/dl, normal thrombocyte count 

3 regions with enlarged lymph nodes 

B Hb 10.0 g/dl, normal thrombocyte count 

3 regions with enlarged lymph nodes 

C Hb 10.0 g/dl and/or thrombocyte count 100 000/µl 

independent of the number of affected locations 

Characteristics of CLL 

Age of onset: Mature adulthood 

Clinical presentation: Gradual enlargement of all lymph nodes, usually 

moderately enlarged spleen, slow onset of anemia and increasing 

susceptibility to infections, later thrombocytopenia 

CBC: In all cases absolute lymphocytosis; in the course of the disease 

Hb , thrombocytes , immunoglobulin 

Further diagnostics: Lymphocyte surface markers (see pp. 68 ff.); bone 

marrow (always infiltrated); lymph node histology further clarifies 

the diagnosis 

Differential diagnosis: (a) Related lymphomas: marker analysis, 

lymph node histology; (b) acute leukemia: cell surface marker analysis, 

cytochemistry, cytogenetics (pp. 88 ff.) 

Course, therapy: Individually varying, usually fairly indolent course; 

in advanced stages or fast progressing disease: moderate chemotherapy 

(cell surface marker, see Table 7) 



a 

c 

Atypical lymphocytes are not part of B-CLL 

Fig. 24 Lymphoma of the B-cell and T-cell lineages. a Prevalence of large lymphocyteswithclearlydefinednucleoliandwidecytoplasm:prolymphocyticleukemiaof 

the B-cell series (B-PLL). b The presence of large blastic cells (arrow) in CLL suggest a 

rare transformation (Richter syndrome). c The rare Sézary syndrome (T-cell lymphoma 

of the skin) is characterized by irregular, indented lymphocytes. d Prolymphocytic 

leukemia of the T-cell series (T-PLL) with indented nuclei and nucleoli 

(rare). e Bone marrow in lymphoplasmacytic immunocytoma: focal or diffuse lymphocyte 

infiltration (e.g., 1), plasmacytoid lymphocytes (e.g., 2) and plasma cells 

(e.g., 3). Red cell precursors predominate (e.g., basophilic erythroblasts, arrow). 



77 

b 

d 

e

78 


The pathological staging for CLL is always Ann Arbor stage IV because the 

bone marrow is affected. In the classifications of disease activity by Rai 

and Binet (analogous to that for leukemic immunocytoma), the transition 

between stages is smooth (Tables 8 and 9). 

Lymphoplasmacytic Lymphoma 

The CBC shows lymphocytes with relatively wide layers of cytoplasm. The 

bone marrow contains a mixture of lymphocytes, plasmacytic lymphocytes, 

and plasma cells. In up to 30% of cases paraprotein is secreted, predominantly 

monoclonal IgM. This constitutes the classic Waldenström 

syndrome (Waldenström macroglobulinemia). The differential diagnosis 

may call for exclusion of the rare plasma cell leukemia (see p. 82) and of 

lymphoplasmacytoid immunocytoma, which is closely related to CLL (see 

p. 74). 


➤ Lymphoplasmacytoid immunocytoma: This is a special form of B- 

CLL in which usually only a few precursors migrate into the bloodstream 

(a lesser degree of malignancy). A diagnosis may only be 

possible on the basis of bone marrow or lymph node analysis. 

➤ Lymphoplasmacytic lymphoma: Few precursors migrate into the 

bloodstream (i.e., bone marrow or lymph node analysis is sometimes 

necessary). There is often secretion of IgM paraprotein, 

which can lead to hyperviscosity. 

Further diagnostics: Marker analyses in circulating cells, lymph node cytology, 

bone marrow cytology and histology, and immunoelectrophoresis. 

Plasmacytoma cells migrate into the circulating blood in appreciable 

numbers in only 1–2% of all cases of plasma cell leukemia. Therefore, paraproteins 

must be analyzed in bone marrow aspirates (p. 82). 

Facultative Leukemic Lymphomas 

(e.g., Mantle Cell Lymphoma and Follicular Lymphoma) 

In all cases of non-Hodgkin lymphoma, the transformed cells may migrate 

into the blood stream. This is usually observed in mantle cell lymphoma: 

The cells are typically of medium size. On close examination, their nuclei 

show loosely structured chromatin and they are lobed with small indentations 

(cleaved cells). Either initially, or, more commonly, during the course 

of the disease, a portion of cells becomes larger with relatively enlarged 

nuclei (diameter 8–12 µm). These larger cells are variably “blastoid.” Lymphoid 

cells also migrate into the blood in stage IV follicular lymphoma. 



Deep nuclear indentation suggests follicular lymphoma or 

mantle cell lymphoma 

a b 

Fig. 25 Mantle cell lymphoma. a Fine, dense chromatin and small indentations 

of the nuclei suggest migration of leukemic mantle cell lymphoma cells into the 

blood stream. b Denser chromatin and sharp indentations suggest migration of 

follicular lymphoma cells into the blood stream. c Diffuse infiltration of the bone 

marrow with polygonal, in some cases indented lymphatic cells in mantle cell 

lymphoma. Bone marrow involvement in follicular lymphoma can often only be 

demonstrated by histological and cytogenetic studies. 



79 

c

80 


“Monocytoid” cells with a wide layer of only faintly staining cytoplasm 

occur in blood in marginal zone lymphadenoma (differential diagnosis: 

lymphoplasmacytic immunocytoma). 

Lymphoma, Usually with Splenomegaly 

(e.g., Hairy Cell Leukemia and Splenic Lymphoma 

with Villous Lymphocytes) 

Hairy cell leukemia (HCL). In cases of slowly progressive general malaise 

with isolated splenomegaly and pancytopenia revealed by CBC (leukocytopenia, 

anemia, and thrombocytopenia), the predominating mononuclear 

cells deserve particular attention. The nucleus is oval, often kidney beanshaped, 

and shows a delicate, elaborate chromatin structure. The cytoplasm 

is basophilic and stains slightly gray. Long, very thin cytoplasmic 

processes give the cells the hairy appearance that gave rise to the term 

“hairy cell leukemia” used in the international literature. The disease affects 

the spleen, liver, and bone marrow. Severe lymphoma is usually absent. 

Aside from the typical hairy cells with their long, thin processes, 

there are also cells with a smooth plasma membrane, similar to cells in immunocytoma. 

A variant shows well-defined nucleoli (HCL-V, hairy cell 

leukemia variant). A bone marrow aspirate often does not yield material 

for an analysis (“punctio sicca” or “empty tap”) because the marrow is very 

fibrous. Apart from the bone marrow histology, advanced cell diagnostics 

are therefore very important, in particular in the determination of blood 

cell surface markers (immunophenotyping). This analysis reveals CD 103 

and 11 c as specific markers and has largely replaced the test for tartrateresistant 

acid phosphatase. 

Splenic lymphoma with villous lymphocytes (SLVL). This lymphatic system 

disease mostly affects the spleen. There is little involvement of the bone 

marrow and no involvement of the lymph nodes. The blood contains lymphatic 

cells, which resemble hairy cells. However, the “hairs,” i.e., cytoplasmic 

processes, are thicker and mostly restricted to one area at the cell 

pole, and the CD 103 marker is absent. 

Splenomegaly may develop in all non-Hodgkin lymphomas. In hairy cell 

leukemia, the rare splenic lymphadenoma with villous lymphocytes 

(SLVL) and marginal zone lymphadenoma may be seen. These mostly affect 

the spleen. 



a 

c 

Cytoplasmic processes the main feature of hairy cell leukemia 

Fig. 26 Hairy cell leukemia and splenic lymphoma. a and b Ovaloid nuclei and 

finely “fraying” cytoplasm are characteristics of cells in hairy cell leukemia (HCL). 

c Occasionally, the hairy cell processes appear merely fuzzy. d and e When the cytoplasmic 

processes look thicker and much less like hair, diagnosis of the rare splenic 

lymphoma with villous lymphocytes (SLVL) must be considered. Here, too, the 

next diagnostic step is analysis of cell surface markers. 



81 

b 

d 

e

82 


Monoclonal Gammopathy (Hypergammaglobulinemia), 

Multiple Myeloma*, Plasma Cell Myeloma, Plasmacytoma 

Plasmacytoma is the result of malignant transformation of the most 

mature B-lymphocytes (Fig. 1, p. 2). For this reason the diagnostics of this 

disease will be discussed here, even though migration of its specific cells 

into the blood stream (plasma cell leukemia) is extremely rare (1–2%). 

Immunoelectrophoresis of serum and urine is performed when electrophoresis 

shows very discrete gammaglobulin, or globulin, fractions, or 

when hypogammaglobulinemia is found (in light-chain plasmacytoma). A 

wide range of possibilities arises for the differential diagnosis of monoclonal 

transformed cells (Table 10). 

The presence of more than 10% of plasma cells, or atypical plasma cells 

in the bone marrow, is an important diagnostic factor in the diagnosis of 

plasmacytoma. For more criteria, see p. 84. 

Table 10 Differential diagnosis of monoclonal hypergammaglobulinemia 

Type Characteristics 

Benign disorders 

➤ Essential hypergammaglobulinemia 

= MGUS (monoclonal gammopathy 

of unknown significance) 

➤ Symptomatic hypergammaglobulinemia, 

secondary to 

– Infections 

– Tumors 

– Autoimmune disease 

Malignant diseases 

➤ Plasmocytoma 

(usually IgG, A or light-chain 

[Bence Jones protein], rarely IgM, 

D, E) 90% disseminated (multiple 

myeloma), 5% solitary, 5% 

extramedullary (like a lymphoma 

or ENT tumor) 

➤ Lymphoma 

e. g., immunocytoma, CLL 

(potentially all lymphomas of the 

B-cell series) 

Usually in advanced age 

10%, plasma cells found in the 

bone marrow, no progression, 

normal polyclonal Ig 

All ages (otherwise as above) 

– Osteolysis or X-ray with severe 

osteoporosis 

– Plasmocytosis of the bone marrow 

10% 

– Monoclonal gammaglobulin in 

serum/urine with progression 

– Enlarged lymph nodes 

– Usually blood lymphocytosis 

– Monoclonal immunoglobulin, 

usually IgM 

* The current WHO classification suggests “multiple myeloma” (MM) for generalized 

plasmacytoma and “plasmacytoma” only for the rare solitary or nonosseous form of 

plasmacytoma. 



Plasmacytoma cannot be diagnosed without bone marrow analysis 

Fig. 27 Reactive plasmacytosis and plasmacytoma. a Bone marrow cytology 

with clear reactive features in the granulocyte series: strong granulation of promyelocytes 

(1) and myelocytes (2), eosinophilia (3), and plasma cell proliferation 

(4): reactive plasmacytosis (magnification 630). b Extensive (about 50%) infiltration 

of the bone marrow of mostly well-differentiated plasma cells: multiple 

myeloma (magnification 400). 



83 

a 

b

84 


Variability of Plasmacytoma Morphology 

It is not easy to visually distinguish malignant cells from normal plasma 

cells. Like lymphocytes, normal plasma cells have a densely structured nucleus. 

Plasma cell nuclei with radial chromatin organization, known as 

“wheel-spoke nuclei,” are mostly seen during histological analysis. 

The following attributes suggest a malignant character of plasma cells: 

the cells are unusually large (Fig. 28 c), they contain crystalline inclusions 

or protein inclusions (“Russell bodies”) (Fig. 28 b), or they have more than 

one nucleus (Fig. 28 c). 

In the differential diagnosis, they must be distinguished from hematopoietic 

precursor cells (Fig. 28 d), osteoblasts (Fig. 20 c), and blasts in acute 

leukemias (see Fig. 31, p. 97). 

Bone marrow involvement may be focal or in rare cases even solitary. 

Aside from cytological tests, bone marrow histology assays are therefore 

indicated. Sometimes, the biopsy must be obtained from a clearly identified 

osteolytic region. 

Although plasmacytomas progress slowly, staging criteria are available 

(staging according to Salmon and Durie) (Table 11). 

Therapy may be put on hold in stage I. Smoldering indolent myeloma 

can be left for a considerable time without the introduction of therapy 

stress. However, chemotherapy is indicated once the myeloma has 

exceeded the stage 1 criteria. 

Table 11 Staging of plasmacytomas according to Salmon and Durie 

Stage I 

All the following are present: 

– Hb 10 g/dl 

– Serum calcium is normal 

– X-ray shows normal bone structure 

or solitary skeletal plasmacytoma 

– IgG 5 g/dl* 

IgA 3 g/dl* 

Light chains in the urine* 

4 g/24 h 

* Monoclonal in each case. 

Stage II 

Findings fulfill neither stage I nor 

stage III criteria 

Stage III 

One or more of the following are 

present: 

– Hb 8.5 g/dl 

– Serum calcium is elevated 

– X-ray shows advanced bone lesions 

– IgG 7 g/dl* 

IgA 5 g/dl* 

Light chains in the urine: 

12 g/24 h 



a 

c 

Atypias and differential diagnoses of multiple myeloma 

Fig. 28 Atypical cells in multiple myeloma. a Extensive infiltration of the bone 

marrow by loosely structured, slightly dedifferentiated plasma cells with wide cytoplasm 

in multiple myeloma. b In multiple myeloma, vacuolated cytoplasmic 

protein precipitates (Russell bodies) may be seen in plasma cells but are without 

diagnostic significance. c Binuclear plasma cells are frequently observed in multiple 

myeloma (1). Mitotic red cell precursor (2). d Differential diagnosis: red cell 

precursor cells can sometimes look like plasma cells. Proerythroblast (1) and basophilic 

erythroblast (2). 



85 

b 

d

86 Abnormalities of the White Cell Series 

Relative Lymphocytosis Associated with 

Granulocytopenia (Neutropenia) and Agranulocytosis 

Neutropenia is defined by a decrease in the number of neutrophilic 

granulocytes with segmented nuclei to less than 1500/µl (1.5 10 9 /l). A 

neutrophil count of less than 500/µl (0.5 10 9 /l) constitutes agranulocytosis. 

Absolute granulocytopenias with benign cause develop into relative 

lymphocytoses. 

In the most common clinical picture, drug-induced acute agranulocytosis, 

the bone marrow is either poor in cells or lacks granulopoietic precursor 

cells (aplastic state), or shows a “maturation block” at the myeloblast–promyelocyte 

stage. The differential diagnosis of pure agranulocytosis 

versus aplasias of several cell lines is outlined on page 146. 

Classification of Neutropenias and Agranulocytoses 

1. Drug-induced: 

a) Dose-independent—acute agranulocytosis. Caused by hypersensitivity 

reactions: for example to pyrazolone, antirheumatic drugs 

(anti-inflammatory agents), antibiotics, or thyrostatic drugs. 

b) Relatively dose-dependent—subacute agranulocytosis (observed for 

carbamazepine [Tegretol], e.g. antidepressants, and cytostatic 

drugs). 

c) Dose-dependent—cytostatic drugs, immunosuppressants. 

2. Infection-induced: 

a) E.g., EBV, hepatitis, typhus, brucellosis. 

3. Autoimmune neutropenia: 

a) With antibody determination of T-cell or NK-cell autoimmune response 

b) In cases of systemic lupus erythematosus (SLE), Pneumocystis carinii 

pneumonia (PCP), Felty syndrome 

c) In cases of selective hypoplasia of the granulocytopoiesis (“pure 

white cell aplasia”) 

4. Congenital and familial neutropenias: 

Various pediatric forms; sometimes not expressed until adulthood, 

e.g. cyclical neutropenia 

5. Secondary neutropenia in bone marrow disease: 

Myelodysplastic syndromes (MDS), e.g., acute leukemia, plasmacytoma, 

pernicious anemia 



Bone marrow diagnosis is indicated in cases of unexplained agranulocytosis 

Fig. 29 The bone marrow in agranulocytosis. a In the early phase of agranulocytosis 

the bone marrow shows only red cell precursor cells (e.g., 1), plasma cells 

(2), and lymphocytes (3); in this sample a myeloblast—a sign of regeneration—is 

already present (4). b Bone marrow in agranulocytosis during the promyelocytic 

phase, showing almost exclusively promyelocytes (e.g., 1); increased eosinophilic 

granulocytes (2) are also present. 



87 

a 

b

88 


Monocytosis 

If mononuclear cells stand out in showing an unusually elaborate nuclear 

structure with ridges and lobes and a wider cytoplasmic layer with very 

delicate granules (for characteristics see p. 46, for cell function, see p. 6), 

and this is in the context of relative ( 10%) or absolute monocytosis (cell 

count 900/µl), a series of possible triggers must be considered (Table 

12). If the morphology does not clearly identify the cells as monocytes, 

then esterase assays should be done in a hematological laboratory using 

unstained smears. 

Table 12 Possible causes of monocytosis 

Infection 

Nonspecific monocytosis occurs in 

many bacterial infections during 

recuperation from or in the chronic 

phase of: 

– Mononucleosis (aside from stimulated 

lymphocytes there are also 

monocytes) 

– Listeriosis 

– Acute viral hepatitis 

– Parotitis epidemica (mumps) 

– Chickenpox 

– Recurrent fever 

– Syphilis 

– Tuberculosis 

– Endocarditis lenta 

– Brucellosis (Bang disease) 

– Variola vera (smallpox) 

– Rocky mountain spotted fever 

– Malaria 

– Paratyphoid fever 

– Kala-azar 

– Thypus fever 

– Trypanosomiasis (African sleeping 

sickness) 

Chronic reactive condition of the 

immune system, e. g., in: 

– Autoimmune diseases 

– Chronic dermatoses 

– Regional ileitis 

– Sarcoidosis 

Paraneoplasm 

(as attempted immune defense), 

e. g., in: 

– Large solid tumors 

– Lymphogranulomatosis 

Neoplasm 

– Chronic myelomonocytic 

leukemia (CMML, p. 107) 

– Acute monocytic leukemia 

(p. 100) 

– Acute myelomonocytic leukemia 

(p. 98) 



Conspicuously large numbers of monocytes usually indicate a 

reactive disorder. Only a monotonous predominance of monocytes 

suggests leukemia 

a b 

Fig. 30 Reactive monocytosis and monocytic leukemia. a Reactive and neoplastic 

monocytes are morphologically indistinguishable; here two relatively condensed 

monocytes in reactive monocytosis are shown. b Whenever monocytes are 

found exclusively, a malignant etiology is likely: in this case AML M5 b according to 

the FAB classification (see p. 100). Auer bodies (arrow). c Monocytes of different 

degrees of maturity, segmented neutrophilic granulocytes (1), and a small myeloblast 

(2) in chronic myelomonocytic leukemia (CMML, see p. 107). 

89 



c

90 


Acute Leukemias 

Acute leukemias are described in this place for morphological reasons, because 

they involve a predominance of mononuclear cells (p. 63). Although—or 

perhaps because—the term “leukemia” is relatively imprecise, 

an overview seems required (Table 13). 

The cellular phenomenon common to the different forms of leukemia is 

the rapidly progressive reduction in numbers of mature granulocytes, 

thrombocytes, and erythrocytes. Simultaneously, the leukocyte count 

usually increases due to the occurrence of atypical round cells. 

Table 13 Overview of all forms of leukemia 

Type of leukemia Classification/clinical findings 

Acute leukemias (ALAML, ALL) 

– Myeloid M0-7 (incl. monocytic, erythroid, 

megakaryoblastic leukemias) 

Always acute disease, often with 

fever and tendency to hemorrhage 

– Lymphocytic There may be lymphoma and thymus 

infiltrates 

Chronic myeloid leukemia (CML) 

– Persistent leukemic diseases of the 

myeloproliferative system (p. 114) 

Chronic lymphocytic leukemia (CLL) 

and other leukemic lymphomas 

– B-CLL (90%), T-CLL (p.74 f.) 

– Prolymphocytic leukemia (p.77) 

– Hairy cell leukemia (p.80) 

Chronic myelomonocytic leukemia 

(CMML) 

– Leukemic form of myelodysplasia 

(p.106) is classified between 

myelodysplasia and myeloproliferative 

diseases 

Chronic disease, usually with 

splenomegaly 

– Chronic lymphocytic leukemia, 

(rarely) prolymphocytic 

leukemia and hairy cell leukemia 

are primary leukemic lymphomas 

with a chronic course. 

All other non-Hodgkin lymphomas 

can develop secondary 

leukemic disease 

Subacute disease with transitions 

into acute forms of myeloid 

leukemia (secondary AML following 

MDS) 




Note that in about one-fourth of all leukemias total leukocyte counts are 

normal, or even reduced, and the atypical round cells affect only the relative 

(differential) blood analysis (“aleukemic leukemia”). 

In all forms of leukemia, the more fluffy layered areas of a smear show that 

the nuclear chromatin structure is not dense and coarse, as in a normal 

lymphocyte nucleus (p. 49), but more delicately structured and irregular, 

often “sand-like”. A careful blood cell analysis should be carried out—perhaps 

with the assistance of a specialist laboratory—before bone marrow 

analysis is performed. 

In most cases, the high leukocyte count facilitates the diagnosis of 

leukemia. Apart from the leukemia-specific blast cells, a variable number 

of segmented neutrophilic granulocytes may also remain, depending on 

the disease progression at the time of diagnosis. This gap in the cell series 

between blasts and mature cells is called “leukemic hiatus.” It is found in 

ALL but not in reactive responses or chronic myeloid leukemia, which 

show a continuous left shift. Morphological or differential diagnosis of 

acute leukemia is followed by the diagnostic work-up that continues with 

cytochemical tests. Immunological identification of leukemia cells is always 

indicated (Table 14). 

Diagnostic work-up when acute leukemia is suspected: 

CBC, cytochemistry, bone marrow. Collection of material to identify cell 

surface markers, cytogenetics, molecular genetics. 

Morphological and Cytochemical Cell Identification 

After a first-line diagnosis of acute leukemia has been arrived at on the 

basis of the cell morphology (see above), the diagnosis must be refined by 

cytochemical testing of blood cells or bone marrow (on fresh smears). 

Table 14 shows a leukemia classification based on both morphological and 

cytochemical criteria. The table shows that a peroxidase test allows 

leukemias to be classified as peroxidase-positive (myeloid or monocytic) 

or peroxidase-negative (lymphoblastic). The next step is the immunological 

classification based on cell markers. 

In routine clinical hematology, the FAB classification (Table 14) will be 

with us for a few more years. 



91

92 

Table 14 Classification of the acute nonlymphatic leukemias by morphology, cytochemistry, and 

immunology 

FAB type* Peroxidase PAS α-Naphthylacetatesterase 

M0 

M1 

M2 

M3 

M4 


AML with minimal 

marker differentiation,undifferentiated 

blasts 

without granules; 

distinguished from 

M1 and ALL only by 

immunophenotyping 

AML with distinct 

marker differentiation 

(but without morphologicaldifferentiation); 

sporadic discrete 

cytoplasmic 

granulation possible 

AML with morphologically 

mature 

cells; 10% of the 

blasts contain very 

small granules 

Acute promyelocytic 

leukemia; the 

predominant promyelocytes 

contain 

copious granules, 

some contain Auer 

bodies; variant M3 

contains few 

granules; peripheral 

bilobal blasts 

Acute myelomonocytic 

leukemia; 

30–80% of bone 

marrow blasts are 

myeloblasts, promyelocytes, 

and 

myelocytes; 20% 

are monocytes; variant 

M4 eosinophilia; 

additional immature 

eosinophils 

with dark granules 

Naphthyl-ASDesterase 

Immunophenotype 

3% CD 13 or 

CD 33 or 

MPO 

CD 79 a 

and cyCD 3 

and cyCD 22 

and CD 61/ 

CD 41 and 

CD 14 

3% Negative 

to fine 

gran. 

3% Negative 

to fine 

gran. 

MPO and 

CD 13/CD 33/ 

CD 65s / 

and CD 14 

MPO and 

CD 13/CD 33/ 

CD 65s/ 

CD 15 / 

and CD 14 

100% MPO and 

CD 13 and 

CD 33 and 

normally CD 

34 and 

HLA-DR 

3% + 

20% 

+ Mixed M 1/ 

M 2 and M 5 



Table 14 Continued 

FAB type* Peroxidase PAS α-Naphthylacetateesterase 

M5 a) Acute monoblasticleukemia; 

monoblasts 

predominant in 

the blood and 

bone marrow 

b) Acute monocytic 

leukemia; 

monocytes in 

the process of 

maturation predominante 

M6 

M7 

Acute erythroid 

leukemia; 50% of 

bone marrow blasts 

are erythropoietic, 

30% myeloblasts 

Acute megakaryocytic 

leukemia; very 

polymorphic, sometimes 

vacuolated 

blasts, some with 

cytoplastic blebs, 

sometimes aggregated 

with thrombocytes 


+++ 

80% 

+++ +++ 

Naphthyl-ASDesterase 

Immunophenotype 

93 

+++ CD 13/CD 33/ 

CD 65/CD 14/ 

CD64 / 

and HLA-DR 

 

Erythroblasts 

Gly A and 

CD 36 

Myeloblasts 

MPO/CD 

13/CD 33/CD 

65s / and 

CD 14 

CD 13/CD 33 

/ und CD 

41 oder CD 

61 

* French American British Classification (FAB) 1976/85 

** A biphenotypic leukemia must be considered a possibility if several additional lymphoblastic 

markers are present 

PAS Periodic acid-Schiff reaction 



94 


Chromosome analysis provides important information. In practice, 

however, the diagnosis of acute leukemia is still based on morphological 

criteria. 

However, where the possibilities of modern therapeutic and prognostic 

methods are fully accessible, new laboratory procedures based on genetic 

and molecular biological testing procedures form part of the diagnostic 

work-up of AML. The current WHO classification takes account of these 

new methods, placing genetic, morphological, and anamnestic findings in 

a hierarchical order (Table 15). 

According to the new WHO classification, blasts account for more than 

20% of cells in acute myeloid leukemia (in contradistinction to myelodysplasias). 

Table 15 WHO classification of AML 

AML with specific 

cytogenetic translocations 

AML with dysplasia in 

more than 1 cell line 

(2 or 3 cell lines 

affected)* 

Therapy-induced AML 

und MDS 

AML that does not fit 

any of the other categories 

– With t(8;21) (q22; q22), AML 1/ETO 

– Acute promyelocytic leukemia (AML M3 with t(15;17) (q22; 

q11-12) and variants, PML/RAR-α 

– With abnormal bone marrow eosinophils and (inv16) 

(p13;q22) or to t(16;16) (p13; q22); CBF/MYH 11 

– With 11q23 (MLL) anomalies 

– With preceding myelodysplastic/myeloproliferative syndrome 

– Without preceding myelodysplastic syndrome 

– After treatment with alkylating agents 

– After treatment with epipodophyllotoxin 

– Other triggers 

– AML, minimal differentiation 

– AML without cell maturation 

– AML with cell maturation 

– Acute myelomonocytic leukemia 

– Acute monocytic leukemia 

– Acute erythroid leukemia 

– Acute megakaryoblastic leukemia 

– Acute panmyelosis with myelofibrosis 

– Myelosarcoma/chloroma 

– Acute biphenotypic leukemia** 

* The dysplasia must be evident in at least 50% of the bone marrow cells and in 2–3 cell lines. 

** Biphenotypic leukemias should be classified according to their immunophenotypes. They 

are grouped between acute lymphocytic and acute myeloid leukemias. 




Acute Myeloid Leukemias (AML) 

95 

Morphological analysis makes it possible to group the predominant 

leukemic cells into myeloblasts and promyeloblasts, monocytes, or atypical 

(lympho)blasts. A morphological subclassification of these main 

groups was put forward in the French–American–British (FAB) classification 

(Table 14). 

In practical, treatment-oriented terms, the most relevant factor is 

whether the acute leukemia is characterized as myeloid or lymphatic. 

Including the very rare forms, there are at least 11 forms of myeloid 

leukemia. 




Acute Myeloblastic Leukemia (Type M0 through M2 in the FAB Classification). 

Morphologically, the cell populations that dominate the CBC and 

bone marrow analyses (Fig. 31) more or less resemble myeloblasts in the 

course of normal granulopoiesis. Differences may be found to varying 

degrees in the form of coarser chromatin structure, more prominently defined 

nucleoli, and relatively narrow cytoplasm. Compared with lymphocytes 

(micromyeloblasts), the analyzed cells may be up to threefold larger. 

In a good smear, the transformed cells can be distinguished from lymphatic 

cells by their usually reticular chromatin structure and its irregular 

organization. Occasionally, the cytoplasm contains crystalloid azurophilic 

needle-shaped primary granules (Auer bodies). Auer bodies (rods) are 

conglomerates of azurophilic granules. A few cells may begin to display 

promyelocytic granulation. Cytochemistry shows that from stage M1 onward, 

more than 3% of the blasts are peroxidase-positive. 

Characteristics of Acute Leukemias 

Age of onset: Any age. 

Clinical findings: Fatigue, fever, and signs of hemorrhage in later 

stages. 

Lymph node and mediastinal tumors are typical only in ALL. 

Generalized involvement of all organs (sometimes including the 

meninges) is always present. 

CBC and laboratory: Hb , thrombocytes , leukocytes usually 

strongly elevated (~ 80%) but sometimes decreased or normal. 

In the differential blood analysis, blasts predominate (morphologies 

vary). 

Beware: Extensive urate accumulation! 

Further diagnostics: Bone marrow, cytochemistry, immunocytochemistry, 

cytogenetics, and molecular genetics. 

Differential diagnosis: Transformed myeloproliferative syndrome 

(e.g., CML) or myelodysplastic syndrome. 

Leukemic non-Hodgkin lymphomas (incl. CLL). 

Aplastic anemias. 

Tumors in the bone marrow (carcinomas, but also rhabdomyosarcoma). 

Course, therapy: Usually rapid progression with infectious complications 

and bleeding. 

Immediate efficient chemotherapy in a hematology facility; bone 

marrow transplant may be considered, with curative intent. 



a 

Fundamental characteristic of acute leukemia: variable blasts 

drive out other cell series 

c 

d 

Fig. 31 Acute leukemia, M0–M2. a Undifferentiated blast with dense, fine chromatin, 

nucleolus (arrow), and narrow basophilic cytoplasm without granules. This 

cell type is typical of early myeloid leukemia (M0–M1); the final classification is 

made using cell surface marker analysis (see Table 14). b The peroxidase reaction, 

characteristic of cells in the myeloid series, shows positive ( 3%) only for stage 

M1 leukemia and higher. The image shows a weakly positive blast (1), strongly positive 

eosinophil (2), and positive myelocyte (3). c and d Variants of M2 leukemia. 

Some of the cells already contain granules (1) and crystal-like Auer bodies (2). 

97 



b


Acute Promyelocytic Leukemia (FAB Classification Type M3 and M3 v). The 

characteristic feature of the cells, which are usually quite large with variably 

structured nuclei, is extensive promyelocytic granulation. Auer rods 

are commonly present. Cytochemistry reveals a positive peroxidase reaction 

for almost all cells. All other reactions are nonspecific. Acute leukemia 

with predominantly bilobed nuclei is classified as a variant of M3 (M3 V). 

The cytoplasm may appear either ungranulated (M3) or very strongly 

granulated (M3 V). 

Acute Myelomonocytic Leukemia (FAB Classification Type M4). Given the 

close relationship between cells in the granulopoietic and the monocytopoietic 

series (see p. 3), it would not be surprising if the these two systems 

showed a common alteration in leukemic transformation. Thus, acute myelomonocytic 

leukemia shows increased granulocytopoiesis (up to more 

than 20% myeloblasts) with altered cell morphologies, together with increased 

monocytopoiesis yielding more than 20% monoblasts or promonocytes. 

Immature myeloid cells (atypical myelocytes to myeloblasts) 

are found in peripheral blood in addition to monocyte-related cells. Cytochemically, 

the classification calls for more than 3% peroxidase-positive 

and more than 20% esterase-positive blasts in the bone marrow. M4 is similar 

to M2; the difference is that in the M4 type the monocyte series is 

strongly affected. In addition to the above characteristics, the M4Eo variant 

shows abnormal eosinophils with dark purple staining granules. 



a 

b 

The diagnosis of acute leukemia is relevant even without further 

subclassification 

d 

f 

Fig. 32 Acute leukemia M3 and M4. a Blood analysis in promyelocytic leukemia 

(M3): copious cytoplasmic granules. b In type M3, multiple Auer bodies are often 

stacked like firewood (so-called faggot cells). c Blood analysis in variant M3 v with 

dumbbell-shaped nuclei. Auer bodies d Bone marrow cytology in acute myelomonocytic 

leukemia M4: in addition to myeloblasts (1) and promyelocytes (2) there 

are also monocytoid cells (3). e In variant M4Eo abnormal precursors of eosinophils 

with dark granules are present. f Esterase as a marker enzyme for the monocyte 

series in M4 leukemia. 

99 



c 

e

100 


Acute Monocytic Leukemia (FAB Classification Types M5 a+b). Two morphologically 

distinct forms of acute monocytic leukemias exist, monoblastic 

and monocytic. In the monoblastic variant M5a, blasts predominate in the 

blood and bone marrow. The blast nuclei show a delicate chromatin structure 

with several nucleoli. Often, only the faintly grayish-blue stained cytoplasm 

hints at their derivation. 

In monocytic leukemia (type M5b), the bone marrow contains promonocytes, 

which are similar to the blasts in monocytic leukemia, but their nuclei 

are polymorphic and show ridges and lobes. Some promonocytes 

show faintly stained azurophilic granules. The peripheral blood contains 

monocytoid cells in different stages of maturation which cannot be distinguished 

with certainty from normal monocytes. Both types are characterized 

by strong positive esterase reactions in over 80% of the blasts, 

whereas the peroxidase reactivity is usually negative, or positive in only a 

few cells. 

Acute Erythroleukemia (FAB Classification Type M6) 

Erythroleukemia is a malignant disorder of both cell series. It is suspected 

when mature granulocytes are virtually absent, but blasts (myeloblasts) 

are present in addition to nucleated erythrocyte precursors, usually 

erythroblasts (for morphology, see p. 33). The bone marrow is completely 

overwhelmed by myeloblasts and erythroblasts (more than 50% of cells in 

the process of erythropoiesis). Bone marrow cytology and cytochemistry 

confirm the diagnosis. Sporadically, some cases show granulopenia, 

erythroblasts, and severely dedifferentiated blasts, which correspond to 

immature red cell precursors (proerythroblasts and macroblasts). 

The differential diagnosis in cases of cytopenia with red blood cell precursors 

found in the CBC must include bone marrow carcinosis, in which 

the bone marrow–blood barrier is destroyed and immature red cells (and 

sometimes white cells) appear in the bloodstream. Bone marrow cytology 

and/or bone marrow histology clarifies the diagnosis. Hemolysis with hypersplenism 

can also show this constellation of signs. 

Fig. 33 Acute leukemia M5 and M6. a In monoblastic leukemia M5 a, blasts with a 

fine nuclear structure and wide cytoplasm dominate the CBC. b Seemingly mature 

monocytes in monocytic leukemia M5 b. c Homogeneous infiltration of the 

bone marrow by monoblasts (M5 a). Only residual granulopoiesis (arrow). d Same 

as c but after esterase staining. The stage M5 a blasts show a clear positive reaction 

(red stain). There is a nonspecific-esterase (NSE)-negative promyelocyte. 



a 

b 

d 

e 

Acute leukemias may also derive from monoblasts or erythroblasts 

Fig. 33 e Same as c Only the myelocyte in the center stains peroxidase-positive 

(brown tint); the monoblasts are peroxidase-negative. f In acute erythrocytic leukemia 

(M6) erythroblasts and myeloblasts are usually found in the blood. This 

image of bone marrow cytology in M6 shows increased, dysplastic erythropoiesis 

(e.g., 1) in addition to myeloblasts (2). 



101 

c 

f

102 


Acute Megakaryoblastic Leukemia (FAB Classification Type M7) 

This form of leukemia is very rare in adults and occurs more often in 

children. It can also occur as “acute myelofibrosis,” with rapid onset of 

tricytopenia and usually small-scale immigration into the blood of dedifferentiated 

medium-sized blasts without granules. Bone marrow 

harvesting is difficult because the bone marrow is very fibrous. Only bone 

marrow histology and marker analysis (fluorescence-activated cell 

sorting, FACS) can confirm the suspected diagnosis. 

The differential diagnosis, especially if the spleen is very enlarged, 

should include the megakaryoblastic transformation of CML or osteomyelosclerosis 

(see pp. 112 ff.), in which blast morphology is very similar. 

AML with Dysplasia 

The WHO classification (p. 94) gives a special place to AML with dysplasia 

in two to three cell series, either as primary syndrome or following a myelodysplastic 

syndrome (see pp. 106) or a myeloproliferative disease (see 

pp. 114 ff.). 

Criteria for dysgranulopoiesis: 50% of all segmented neutrophils 

have no granules or very few granules, or show the Pelger anomaly, or are 

peroxidase-negative. 

Criteria for dyserythropoiesis: 50% of the red cell precursor cells 

display one of the following anomalies: karyorrhexis, megaloblastoid 

traits, more than one nucleus, nuclear fragmentation. 

Criteria for dysmegakaryopoiesis: 50% of at least six megakaryocytes 

show one of the following anomalies: micromegakaryocytes, more 

than one separate nucleus, large mononuclear cells. 

Hypoplastic AML 

Sometimes (mostly in the mild or “aleukemic” leukemias of the FAB or 

WHO classifications), the bone marrow is largely empty and shows only a 

few blasts, which usually occur in clusters. In such a case, a very detailed 

analysis is essential for a differential diagnosis versus aplastic anemia (see 

pp. 148 f.). 



a 

c 

New WHO classification: AML with dysplasia and hypoplastic 

AML 

Fig. 34 AML with dysplasia and hypoplastic AML. a AML with dysplasia: megaloblastoid 

(dysplastic) erythropoiesis (1) and dysplastic granulopoiesis with Pelger- 

Huët forms (2) and absence of granulation in a myelocyte (3). Myeloblast (4). 

b Multiple separated nuclei in a megakaryocyte (1) in AML with dysplasia. Dyserythropoiesis 

with karyorrhexis (2). c and d Hypoplastic AML. c Cell numbers below 

normal for age in the bone marrow. d Magnification of the area indicated in c, 

showing predominance of undifferentiated blasts (e.g., 1). 



103 

b 

d

104 


Acute Lymphoblastic Leukemia (ALL) 

ALL are the leukemias in which the cells do not morphologically resemble 

myeloblasts, promyelocytes, or monocytes, nor do they show the corresponding 

cytochemical pattern. Common attributes are a usually slightly 

smaller cell nucleus and denser chromatin structure, the grainy consistency 

of which can be made out only with optimal smear technique (i.e., 

very light). The classification as ALL is based on the (often remote) similarities 

of the cells to lymphocytes or lymphoblasts from lymph nodes, and 

on their immunological cell marker behavior. Insufficiently close morphological 

analysis can also result in possible confusion with chronic lymphocytic 

leukemia (CLL), but cell surface marker analysis (see below) will correct 

this mistake. Advanced diagnostics start with peroxidase and esterase 

tests on fresh smears, performed in a hematology laboratory, together 

with (as a minimum) immunological marker studies carried out on fresh 

heparinized blood samples in a specialist laboratory. The detailed differentiation 

provided by this cell surface marker analysis has prognostic implications 

and some therapeutic relevance especially for the distinction to 

bilineage leukemia and AML (Table 16). 

Table 16 Immunological classification of acute bilineage leukemias (adapted from Bene MC 

et al. (1995) European Group for the Immunological Characterization of Leukemias (EGIL) 9: 

1783–1786) 

Score B-lymphoid T-lymphoid Myeloid 

2 CytCD79a* CD3(m/cyt) MP0 

Cyt IgM anti-TCR 

1 CD19 CD2 CD117 

CD20 CD5 CD13 

CD10 CD8 CD33 

CD10 CD65 

0.5 TdT TdT CD14 

CD24 CD7 CD15 

CD1a CD64 

* CD79a may also be expressed in some cases of precursor T-lymphoblastic leukemia/lymphoma. 



a 

The cells in acute lymphocytic leukemia vary, and the subtypes 

can be reliably identified only by immunological methods 

c 

d 

Fig. 35 Acute lymphocytic leukemias. a Screening view: blasts (1) and lymphocytes 

(2) in ALL. Further classification of the blasts requires immunological methods 

(common ALL). b Same case as a . The blasts show a dense, irregular nuclear 

structure and narrow cytoplasm (cf. mononucleosis, p. 69). Lymphocyte (2). c ALL 

blasts with indentations must be distinguished from small-cell non-Hodgkin 

lymphoma (e.g., mantle cell lymphoma, p. 77) by cell surface marker analysis. 

d Bone marrow: large, vacuolated blasts, typical of B-cell ALL. The image shows 

residual dysplastic erythropoietic cells (arrow). 

105 



b

106 


Myelodysplasia (MDS) 

Clinical practice has long been familiar with the scenario in which, after 

years of bone marrow insufficiency with a more or less pronounced deficit 

in all three cell series (tricytopenia), patients pass into a phase of insidiously 

increasing blast counts and from there into frank leukosis 

—although the evolution may come to a halt at any of these stages. The 

transitions between the forms of myelodysplastic syndromes are very 

fluid, and they have the following features in common: 

➤ Anemia, bicytopenia, or tricytopenia without known cause. 

➤ Dyserythropoiesis with sometimes pronounced erythrocyte anisocytosis; 

in the bone marrow often megaloblastoid cells and/or ring sideroblasts. 

➤ Dysgranulopoiesis with pseudo-Pelger-Huët nuclear anomaly (hyposegmentation) 

and hypogranulation (often no peroxidase reactivity) of 

segmented and band granulocytes in blood and bone marrow. 

➤ Dysmegakaryopoiesis with micromegakaryocytes. 

The FAB classification is the best-known scheme so far for organizing the 

different forms of myelodysplasia (Table 17). 

Table 17 Forms of myelodysplasia 

Form of myelodysplasia Blood analysis Bone marrow 

RA = refractory anemia Anemia (normochromic 

or hyperchromic); 

possibly 

pseudo-Pelger granulocytes; 

blasts 1% 

RAS = refractory anemia 

with ring sideroblasts 

( aquired 

idiopathic sideroblastic 

anemia, p. 137) 

RAEB = refractory anemia 

with excess of 

blasts 

Hypochromic and 

hyperchromic erythrocytes 

side by side, 

sometimes discrete 

thrombopenia and 

leukopenia; pseudo- 

Pelger cells 

Often thrombocytopenia 

in addition to 

anemia; blasts 5%, 

monocytes 1000/µl, 

pseudo-Pelger syndrome 

Dyserythropoiesis 

(marginal dysgranulopoiesis 

and dysmegakaryopoiesis 

10%) 

5% blasts 

More than 15% of the 

red cell precursors are 

ring sideroblasts; 

blasts 5% 

Erythropoietic hyperplasia 

(with or without 

ring sideroblasts); 

5–20% blasts 



Cont. p. 108

a 

c 

In unexplained anemia and/or leukocytopenia and/or thrombocytopenia, 

blood cell abnormalities may indicate myelodysplasia 

Fig. 36 Myelodysplasia and CMML. a–d Different degrees of abnormal maturation 

(pseudo-Pelger type); the nuclear density can reach that of erythroblasts 

(d). The cytoplasmic hypogranulation is also observed in normal segmented granulocytes. 

These abnormalities are seen in myelodysplasia or after chemotherapy, 

among other conditions. e Blood analysis in CMML: monocytes (1), promyelocyte 

(2), and pseudo-Pelger cell (3). Thrombocytopenia. 



107 

b 

d 

e

108 


Table 17 Continued 

Form of myelodysplasia Blood analysis Bone marrow 

CMML = chronic myelomonocytic 

leukemia 

RAEB in transformation 

(RAEBt)* 

Blasts 5%, monocytes 

1000/µl, 

pseudo-Pelger syndrome 

Similar to RAEB but 

5% blasts 

Hypercellular, blasts 

20%, elevated promonocytes 

Blasts 20–30% (some 

cells contain Auer 

bodies) 

* In the WHO classification, the category RAEBt would belong to the category of acute myeloid 

leukemia. 

The new WHO classification of myelodysplastic syndromes defines the 

differences in cell morphology even more precisely than the FAB classification 

(Table 18). 

For the criteria of dysplasia, see page 106. 

The “5q- syndrome” is highlighted as a specific type of myelodysplasia 

in the WHO classification; in the FAB classification it would be a subtype of 

RA and RAS. A macrocytic anemia, the 5q- syndrome manifests with normal 

or increased thrombocyte counts while the bone marrow contains 

megakaryocytes with hyposegmented round nuclei (Fig. 37 b). 

Naturally, bone marrow analysis is of particular importance in the myelodysplasias. 

Table 18 WHO classification of myelodysplastic syndromes 

Disease* Dysplasia** Blasts in 

peripheral 

blood 

Blasts in the 

bone marrow 

Ring sideroblasts 

in the 

bone marrow 

Cytogenetics 

5q- syndrome Usually only E 5% 5% 15% 5q only 

RA Usually only DysE 1% 5% 15% Variable 

RARS Usually only DysE None 5% 15% Variable 

RCMD 2–3 lines Rarely 5% 15% Variable 

RCMD-RS 2–3 lines Rarely 5% 15% Variable 

RAEB-1 1–3 lines 5% 5–9% 15% Variable 

RAEB-2 1–3 lines 5–19% 10–19% 15% Variable 

CMML-1 1–3 lines 5% 10% 15% Variable 

CMML-2 1–3 lines 5–19% 10–19% 15% Variable 

MDS-U 1 cell lineage None 5% 15% Variable 

* RA = refractory anemia; RARS = refractory anemia with ring sideroblasts; RCMD = refractory 

cytopenia with more than one dysplastic cell line; RCMD-RC = refractory cytopenia with more 

than one dysplastic lineage and ring sideroblasts; RAEB = refractory anemia with elevated blast 

count; CMML = chronic myelomonocytic leukemia, persistent monocytosis (more than 

1 10 9 /l) in peripheral blood; MDS-U = MDS, unclassifiable. ** Dysplasia in granulopoiesis 

= Dys G, in erythropoiesis = DysE, in megakaryopoiesis = DysM, multilineage dysplasia 

= two cell lines affected; trilineage dysplasia (TLD) = all three lineage show dysplasia. 



a 

The classification of myelodysplasias requires bone marrow analysis 

c 

d 

Fig. 37 Bone marrow analysis in myelodysplasia. a Dysmegakaryopoiesis in 

myelodysplastic syndrome (MDS). Relatively small disk-forming megakaryocytes 

(1) and multiple singular nuclei (2) are often seen. b Mononuclear megakaryocytes 

(frequent in 5q-syndrome). c Dyserythropoiesis. Particularly striking is the 

coarse nuclear structure with very light gaps in the chromatin (arrow 1). Some are 

megaloblast-like but coarser (arrow 2). d Iron staining of the bone marrow (Prussian 

blue) in myelodysplasia of the RARS type: dense iron granules forming a partial 

ring around the nuclei (ring sideroblasts). 

109 



b

110 

Table 19 Diagnostic work-up for anomalies in the white cell series with polynucleated 

(segmented) cells predominating 

Clinical findings Hb MCH Leukocytes 

Acute temperature, 

possibly 

focal signs 

Patient smokes 

heavily (no 

splenomegaly) 

Slowly developing 

fatigue, 

spleen 

Slowly developing 

fatigue, 

spleen 

Segmented 

cells 

(%) 

Lymphocytes 

(%) 

Other cells 

n n Left shift 

n/ n 

/n /n Left shift 

n// n// Normoblasts, 

left shift 

n Some normoblasts 

Pruritus or 

exanthema 


Prevalence of Polynuclear 

(Segmented) Cells (Table 19) 

Neutrophilia without Left Shift 

For clarity, conditions in which mononuclear cells (lymphocytes, monocytes) 

predominate were in the previous section kept distinct from hematological 

conditions in which cells with segmented nuclei and, in some 

cases, their precursors predominate. Leukocytosis with a predominance 

of segmented neutrophilic granulocytes without the less mature forms is 

called granulocytosis or neutrophilia. 

n n n/ n n 

Eosinophils 

Diagnostic steps proceed from left to right. ⎪ The next step is usually unnecessary; the next step 

is obligatory. 



Causes of Neutrophilia 

➤ All kinds of stress 

➤ Pregnancy 

➤ Connective tissue diseases 

➤ Tissue necrosis, e.g., after myocardial or pulmonary infarction 

➤ Acidosis of various etiologies, e.g., nephrogenic diabetes insipidus 

➤ Medications, drugs, or noxious chemicals, such as 

– Nicotine 

– Corticosteroids 

– Adrenaline 

– Digitalis 

– Allopurinol 

Thrombocytes 

Electrophoresis 

Prevalence of Polynuclear (Segmented) Cells 

Tentative 

diagnosis 

n n Acute bacterial 

infection 

(possibly with 

leukemoid 

reaction) 

n/ n Smoker’s 

leukocytosis 

n// n Chronic 

myeloid 

leukemia 

(CML) 

n// n Osteomyelosclerosis 

n/ n Polycythemia 

with concomitantleukocytosis 

n n Reactive 

eosinophilia 

– Barbiturates 

– Lithium 

– Streptomycin 

– Sulfonamide 

Evidence/advanced 

diagnostics 

Search for disease 

focus 

Bone 

marrow 

Anamnesis In progressive 

disease: bone 

marrow analysis 

(DD myeloproliferative 

disease) 

Cytogenetics, 

BCR-ABL 

Tear-drop-shaped 

erythrocytes 


focus/allergen 

Complete 

bone marrow 

analysis, all 

fractions 

Often dry tap 

bone marrow 

histology 



Ref. 

page 

p. 112 

p. 112 

p. 116 

p. 122 

p. 162 

p. 124 

111

112 


Reactive Left Shift 

A relative left shift in the granulocyte series means less mature forms in 

excess of 5% band neutrophils; the preceding, less differentiated cell forms 

are included and all transitional forms are taken into account. This left 

shift almost always indicates an increase in new cell production in this cell 

series. In most cases, it is associated with a raised total leukocyte count. 

However, since total leukocyte counts are subject to various interfering 

factors that can also alter the cell distribution, left shift without leukocytosis 

can occur, and has no further diagnostic value. At best, if no other explanations 

offer, a left shift without leukemia can prompt investigation for 

splenomegaly, which would have prevented elevation of the leukocyte 

count by increased sequestration of leukocytes as in hypersplenism. 

In evaluating the magnitude of a left shift, the basic principle is that the 

more immature the cell forms, the more rarely they appear; and that there 

is a continuum starting from segmented granulocytes and sometimes 

reaching as far as myeloblasts. Accordingly, a moderate left shift of medium 

magnitude may include myelocytes and a severe left shift may go as 

far as a few promyelocytes and (very rarely) myeloblasts, all depending on 

how fulminant the triggering process is and how responsive the individual. 

The term “pathological left shift” (for a left shift that includes 

promyelocytes and myeloblasts) is inappropriate, because such observations 

can reflect a very active physiological reaction, perhaps following a 

“leukemoid reaction” with pronounced left shift and leukocytosis. 

Causes of Reactive Left Shift 

Left shift occurs regularly in the following situations: 

➤ Bacterial infections (including miliary tuberculosis), 

➤ Nonbacterial inflammation (e.g., colitis, pancreatitis, phlebitis, and 

connective tissue diseases) 

➤ Cell breakdown (e.g., burns, liver failure, hemolysis) 

Left shift sometimes occurs in the following situations: 

➤ Infection with fungi, mycoplasm, viruses, or parasites 

➤ Myocardial or pulmonary infarction 

➤ Metabolic changes (e.g., pregnancy, acidosis, hyperthyroidism) 

➤ Phases of compensation and recuperation (hemorrhages, hemolysis, 

or after medical or radiological immunosuppression). 



a 

c 

Predominance of the granulocytic lineage with copious granulation 

and sporadic immature cells: usually a reactive left shift 

Fig. 38 Left shift. a and b Typical blood smear after bacterial infection: toxic granulation 

in a segmented granulocyte (1), monocyte with gray–blue cytoplasm 

(2), metamyelocyte (3), and myelocyte (4). c Blood analysis in sepsis: promyelocyte 

(1) and orthochromatic erythroblast (2). Thrombocytopenia. d and e Reactive 

left shift as far as promyelocytes (1). Particularly striking are the reddish granules 

in a band neutrophilic granulocyte (2). 



113 

b 

d 

e

114 


Chronic Myeloid Leukemia and Myeloproliferative 

Syndrome (Chronic Myeloproliferative Disorders, 

CMPD) 

The chronic myeloproliferative disorders (previously also called the myeloproliferative 

syndromes) include chronic myeloid leukemia (CML), 

osteomyelosclerosis (OMS), polycythemia vera (PV) and essential thrombocythemia 

(ET). Clearly, noxious agents of unknown etiology affect the 

progenitor cells at different stages of differentiation and trigger chronic 

malignant proliferation in the white cell series (CML), the red cell series 

(PV), and the thrombocyte series (ET). Sometimes, they lead to concomitant 

synthesis of fibers (OMS). Transitional forms and mixed forms exist 

particularly between PV, ET, and OMS. 

The chronic myeloproliferative disorders encompass chronic autonomous 

disorders of the bone marrow and the embryonic blood-generating 

organs (spleen and liver), which may involve one or several cell lines. 

The common attributes of these diseases are onset in middle age, development 

of splenomegaly, and slow disease progression (Table 20). 

In 95% of cases, CML shows a specific chromosome aberration 

(Philadelphia chromosome with a specific BCR-ABL translocation) and 

may make the transition into a blast crisis. 

PV and ET often show similar traits (high thrombocyte count or high 

Hb) and have a tendency to secondary bone marrow fibrosis. OMS is primarily 

characterized by fibrosis in bone marrow and splenomegaly (see 

p. 122). 



115 

Table 20 Clinical characteristics and differential diagnostic criteria in chronic 

myeloproliferative disease 

Splenomegaly 

Changes in 

the CBC for 

granulopoiesis 

and/or 

erythropoiesis 

Thrombocytes 

Bone marrow 

cytology 

Bone marrow 

histology 

Philadelphia 

chromosome 

Other chromosomal 

alterations 

Alkaline 

Leukocytephosphatase 

(ALP) 

Vitamin B12 

900 pg/ml 

CML 

(see p. 116) 

PV 

(see p. 162) 

OMS 

(see p. 122) 

+ No + No 

Leukocytosis 

with left shift, 

eosinophilia, 

basophilia !! 

Leukocytosis, 

hematocrit 

!! 

() () 

Giant forms 

Very hypercellular, 

basophilia, 

megakaryocytes, 

and 

eosinophilia 

 

Prevalence of Polynuclear (Segmented) Cells 


, megakaryocytes 

 

Markedly 

hypercellular, 

erythropoiesis 

Number of 

cells 

Tear-dropshapederythrocytes, 

left 

shift in the 

granulopoiesis, 

normoblasts 

ET 

(see p. 170) 

No 

to () 450 000/ 

µl ! 

giant forms 

In most cases 

dry tap 

Advanced 

fibrosis ! 

Yes! No No No 

In the acceleration 

phase 

and blast crisis 

del (20q), +8, 

+9, +1q, and 

others 

-7, +8, +9, 

+1q, and others 


clearly 

elevated 

and 

arranged 

in nests 


clearly 

elevated, 

arranged 

in nests 

Very rare 

! Normal to Normal to 

 

Normal Normal 



116 


Characteristics of CML 

Age of onset: Any age. Peak inicidence about 50 years. 

Clinical findings: Slowly developing fatigue, anemia; in some cases 

palpable splenomegaly; no fever. 

CBC: Leukocytosis and a left shift in the granulocyte series; possibly 

Hb , thrombocytes or . 

Advanced diagnostics: Bone marrow, cytogenetics, and molecular 

genetics (Philadelphia chromosome and BCR-ABL rearrangement). 

Differential diagnosis: Reactive leukocytoses (alkaline phosphatase, 

trigger?); other myeloproliferative disorders (bone marrow, cytogenetics, 

alkaline phosphatase). 

Course, therapy: Chronic progression. Acute transformation after 

years. New, curative drugs are currently under development. Evaluate 

the possibility of a bone marrow transplant (up to age approx. 60 

years). 

Steps in the Diagnosis of Chronic Myeloid Leukemia 

Left-shift leukocytosis in conjunction with usually low-grade anemia, 

thrombocytopenia or thrombocytosis (which often correlates with the 

migration of small megakaryocyte nuclei into the blood stream), and clinical 

splenomegaly is typical of CML. LDH and uric acid concentrations are 

elevated as a result of the increased cell turnover. 

The average “typical” cell composition is as follows (in a series analyzed 

by Spiers): about 2% myeloblasts, 3% promyelocytes, 24% myelocytes, 8% 

metamyelocytes, 57% band and segmented neutrophilic granulocytes, 3% 

basophils, 2% eosinophils, 3% lymphocytes, and 1% monocytes. 

In almost all cases of CML the hematopoietic cells display a marker 

chromosome, an anomalously configured chromosome 22 (Philadelphia 

chromosome). The translocation responsible for the Philadelphia chromosome 

corresponds to a special fusion gene (BCR-ABL) that can be determined 

by polymerase chain reaction (PCR) and fluorescence in situ hybridization 

(FISH). 



a 

Left shift as far as myeloblasts, proliferation of eosinophils and 

basophils suggest chronic myeloid leukemia (CML) 

b c 

Fig. 39 CML. a Blood analysis in chronic myeloid leukemia (chronic phase): segmented 

neutrophilic granulocytes (1), band granulocyte (2) (looks like a metamyelocyte 

after turning and folding of the nucleus), myelocyte with defective granulation 

(3), and promyelocyte (4). b and c Also chronic phase: myeloblast (1), 

promyelocyte (2), myelocyte with defective granulation (3), immature eosinophil 

(4), and basophil (5) (the granules are larger and darker, the nuclear chromatin 

denser than in a promyelocyte). 



117

118 


Bone Marrow Analysis in CML. In many clinical situations, the findings 

from the CBC, the BCR-ABL transformation and the enlarged spleen unequivocally 

point to a diagnosis of CML. Analysis of the bone marrow 

should be performed because it provides a series of insights into the disease 

processes. 

Normally, the cell density is considerably elevated and granulopoietic 

cells predominate in the CBC. Cells in this series mature properly, apart 

from a slight left shift in the chronic phase of CML. CML differs from reactive 

leukocytoses because there are no signs of stress, such as toxic granulation 

or dissociation in the nuclear maturation process. 

Mature neutrophils may occasionally show pseudo-Pelger forms (p. 43) 

and the eosinophilic and, especially, basophilic granulocyte counts are 

often elevated. The proportion of cells from the red blood cell series 

decreases. Histiocytes may store glucocerebrosides, as in Gaucher syndrome 

(pseudo-Gaucher cells), or lipids in the form of sea-blue precipitates 

(sea-blue histiocytes after Romanowsky staining). 

Megakaryocytes are usually increased and are often present as micromegakaryocytes, 

with one or two nuclei which are only slightly larger than 

those of promyelocytes. Their cytoplasm typically shows clouds of 

granules, as in the maturation of thrombocytes. 



a 

Bone marrow analysis is not obligatory in chronic myeloid leukemia, 

but helps to distinguish between the various chronic myeloproliferative 

disorders 

b c 

Fig. 40 Bone marrow cytology in CML. a Bone marrow cytology in the chronic 

phase: increased cell density due to increased, left-shifted granulopoiesis, e.g., 

promyelocyte nest (1) and megakaryopoiesis (2). Eosinophils are increased (arrows), 

erythropoiesis reduced. b Often micromegakaryocytes are found in the 

bone marrow cytology. c Pseudo-Gaucher cells in the bone marrow in CML. 



119

120 


Blast Crisis in Chronic Myeloid Leukemia 

During the course of CML with or without therapy, regular monitoring of 

the differential smear is particularly important, since over periods of varying 

duration the relative proportions of blasts and promyelocytes increases 

noticeably. When the blast and promyelocyte fractions together 

make up 30%, and at the same time Hb has decreased to less than 10 g/dl 

and the thrombocyte count is less than 100 000/µl, an incipient acute blast 

crisis must be assumed. this blast crisis is often accompanied or preceded 

by a markedly increased basophil count. Further blast expansion—usually 

largely recalcitrant to treatment—leads to a clinical picture not always 

clearly distinguishable from acute leukemia. If in the chronic phase the 

disease was “latent” and medical treatment was not sought, enlargement 

of the spleen, slight eosinophilia and basophilia, and the occasional presence 

of normoblasts, together with the overwhelming myeloblast fraction, 

are all signs indicating CML as the cause of the blast crisis. 

As in AML, in two-thirds of cases cytological and immunological tests 

are able to identify the blasts as myeloid. In the remaining one-third of 

cases, the cells carry the same markers as cells in ALL. This is a sign of dedifferentiation. 

A final megakaryoblastic or a final erythremic crisis is extremely 

rare. 

Bone marrow cytology is particularly indicated when clinical symptoms 

such as fatigue, fever, and painful bones suggest an acceleration of CML 

which is not yet manifest in the CBC. In such a case, bone marrow analysis 

will frequently show a much more marked shift to blasts and promyelocytes 

than the CBC. A proportion of more than 20% immature cell fractions 

is sufficient to diagnose a blast crisis. 

The prominence of other cell series (erythropoiesis, thrombopoiesis) is 

reduced. The basophil count may be elevated. 

A bone marrow aspiration may turn out to be empty (sicca) or scarcely 

yield any material. This suggests fibrosis of the bone marrow, which is 

frequently a complicating symptom of long-standing disease. Staining of 

the fibers will demonstrate this condition in the bone marrow histology. 



a 

In the course of chronic myeloid leukemia, an acute crisis may 

develop in which blasts predominate 

b c 

Fig. 41 Acute blast crisis in CML. a Myeloblasts (1) with somewhat atypical nuclear 

lobes. Basophilic granulocyte (2) and band granulocyte (3). Thrombocytopenia. 

The proliferation of basophilic granulocytes often precedes the blast crisis. 

b Myeloblasts in an acute CML blast crisis. Typical sand-like chromatin structure 

with nucleoli. A lymphocyte. c Bone marrow cytology in acute CML blast crisis: 

blasts of variable sizes around a hyperlobulated megakaryocyte (in this case during 

a lymphatic blast crisis). 



121

122 


Osteomyelosclerosis 

When anemia accompanied by moderately elevated (although sometimes 

reduced) leukocyte counts, thrombocytopenia or thrombocytosis, clinically 

evident splenic tumor, left shift up to and including sporadic myeloblasts, 

and eosinophilia, the presence of a large proportion of red cell precursors 

(normoblasts) in the differential blood analysis, osteomyelosclerosis 

should be suspected. BCR-ABL gene analysis is negative. 

Pathologically, osteomyelosclerosis usually originates from megakaryocytic 

neoplasia in the bone marrow and the embryonic hematopoietic 

organs, particularly spleen and liver, accompanied by fibrosis 

(= sclerosis) that will eventually predominate in the surrounding tissue. 

The central role of cells of the megakaryocyte series is seen in the giant 

thrombocytes, or even small coarsely structured megakaryocyte nuclei 

without cytoplasm, that migrate into the blood stream and appear in the 

CBC. OMS can be a primary or secondary disease. It may arise during the 

course of other myeloproliferative diseases (often polycythemia vera or 

idiopathic thrombocythemia). 

Tough, fibrous material hampers the sampling of bone marrow material, 

which rarely yields individual cells. This in itself contributes to the 

bone marrow analysis, allowing differential diagnosis versus reactive fibroses 

(parainfectious, paraneoplastic). 

Characteristics of OMS 

Age of onset: Usually older than 50 years. 

Clinical findings: Signs of anemia, sometimes skin irritation, drastically 

enlarged spleen. 

CBC: Usually tricytopenia, normoblasts, and left shift. 

Further diagnostic procedures: Fibrous bone marrow (bone marrow 

histology), when appropriate and BCR-ABL (always negative). 

Differential diagnosis: Splenomegaly in cases of lymphadenoma or 

other myeloproliferative diseases: bone marrow analysis. 

Myelofibrosis in patients with metastatic tumors or inflammation: 

absence of splenomegaly. 

Course, therapy: Chronic disease progression; transformation is rare. 

If there is splenic pressure: possibly chemotherapy, substitution therapy. 

Further myeloproliferative diseases are described together with the relevant 

cell systems: polycythemia vera (see p. 162) and essential thrombocythemia 

(see p. 170). 



a 

c 

Enlarged spleen and presence of immature white cell precursors 

in peripheral blood suggest osteomyelosclerosis 

Fig. 42 Osteomyelosclerosis (OMS). a and b Screening of blood cells in OMS: red 

cell precursors (orthochromatic erythroblast = 1 and basophilic erythroblast = 2), 

basophilic granulocyte (3), and teardrop cells (4). c Sometimes small, dense 

megakaryocyte nuclei are also found in the blood stream in myeloproliferative 

diseases. d Blast crisis in OMS: myeloblasts and segmented basophilic granulocytes 

(1). 



123 

b 

d

124 


Elevated Eosinophil and Basophil Counts 

In accordance with their physiological role, an increase in eosinophils 

( 400/µl, i.e. for a leukocyte count of 6000, more than 8% in the differential 

blood analysis) is usually due to parasitic attack (p. 5). In the Western 

hemisphere, parasitic infestations are investigated on the basis of stool 

samples and serology. 

Strongyloides stercoralis in particular causes strong, sometimes extreme, 

elevation of eosinophils (may be up to 50%). However, eosinophilia of 

variable degree is also seen in ameba infection, in lambliasis (giardiasis), 

schistosomiasis, filariasis, and even malaria. 

Bacterial and viral infections are both unlikely ever to lead to eosinophilia 

except in a few patients with scarlet fever, mononucleosis, or infectious 

lymphocytosis. The second most common group of causes of eosinophilia 

are allergic conditions: these include asthma, hay fever, and various dermatoses 

(urticaria, psoriasis). This second group also includes druginduced 

hypersensitivity with its almost infinitely multifarious triggers, 

among which various antibiotics, gold preparations, hydantoin derivatives, 

phenothiazines, and dextrans appear to be the most prevalent. 

Eosinophilia is also seen in autoimmune diseases, especially in 

scleroderma and panarteritis. All neoplasias can lead to “paraneoplastic” 

eosinophilia, and in Hodgkin’s disease it appears to play a special role in 

the pathology, although it is nevertheless not always present. 

A specific hypereosinophilia syndrome with extreme values (usually 

40%) is seen clinically in association with various combinations of 

splenomegaly, heart defects, and pulmonary infiltration (Loeffler syndrome), 

and is classified somewhere between autoimmune diseases and 

myeloproliferative syndromes. Of the leukemias, CML usually manifests 

moderate eosinophilia in addition to its other typical criteria (see p. 114). 

When moderate eosinophilia dominates the hematological picture, the 

term chronic eosinophilic leukemia is used. Acute, absolute predominance 

of eosinophil blasts with concomitant decrease in neutrophils, erythrocytes, 

and thrombocytes suggests the possibility of the very rare acute 

eosinophilic leukemia. 

Elevated Basophil Counts. Elevation of segmented basophils to more than 

2–3% or 150/µl is rare and, in accordance with their physiological role in 

the immune system regulation, is seen inconsistently in allergic reactions 

to food, drugs, or parasites (especially filariae and schistosomes), i.e., usually 

in conditions in which eosinophilia is also seen. Infectious diseases 

that may show basophilia are tuberculosis and chickenpox; metabolic diseases 

where basophilia may occur are myxedema and hyperlipidemia. Autonomic 

proliferations of basophils are part of the myeloproliferative 



a 

b 

Eosinophilia and basophilia are usually accompanying phenomena 

in reactive and myeloproliferative disorders, especially 

CML 

c d 

Fig. 43 Eosinophilia and basophilia. a Screening view of blood cells in reactive 

eosinophilia: eosinophilic granulocytes (1), segmented neutrophilic granulocyte 

(2), and monocyte (3) (reaction to bronchial carcinoma). b and c The image shows 

an eosinophilic granulocyte (1) and a basophilic granulocyte (2) (clinical osteomyelosclerosis). 

d Bone marrow in systemic mastocytosis: tissue mast cell (3), 

which, in contrast to a basophilic granulocyte, has an unlobed nucleus, and the cytoplasm 

is wide with a tail-like extension. Tissue mast cells contain intensely basophilic 

granules. 

125 



126 

Table 21 Different forms of benign and malignant proliferation of tissue mast 

cells 

Clinical picture Clinical diagnosis Evidence 

In childhood, solitary or 

multiple skin nodules, 

some brownish 

Sometimes transition 

Diffuse brownish papules, 

with urticaria on irritation 

 

Hyperpigmented spots, 

papules and/or dermographism; 

histamine 

symptoms: flushing, headache, 

pruritus, abdominal 

spasms, shock 

 

Malignant transformation, 

possibly with osteolysis, 

enlarged lymph nodes, 

splenomegaly, hepatomegaly 

 


pathologies and can develop to the extent of being termed “chronic basophilic 

leukemia.” In the very rare acute basophilic leukemia, the cells in 

the basophilic granulocyte lineage mature in the bone marrow only to the 

stage of promyelocytes, giving a picture similar to type M3 AML (p. 98). 

Being an expression of idiopathic disturbance of bone marrow function, 

elevated basophil counts are a relatively constant phenomenon in myeloproliferative 

syndromes (in addition to the specific signs of these diseases), 

especially in CML. Acute basophilic leukemia is extremely rare; in this 

condition, some of the dedifferentiated blasts contain more or less basophilic 

granules. 

The tissue-bound analogs of the segmented basophils, the tissue mast 

cells, can show benign or malignant cell proliferation, including the (extremely 

rare) acute mast cell leukemia (Table 21). 

Migration of leukemic cells 

to peripheral blood 

Localized mastocytosis Histology 

Urticaria pigmentosa Typical clinical 

picture 

Systemic mastocytosis Histology 

Malignant mastocytosis* 

Acute mast cell 

leukemia 

Histology 

* May occur de novo without preceding stages and without skin involvement. 

CBC (bone marrow) 



Erythrocyte and Thrombocyte 

Abnormalities 



128 

Erythrocyte and Thrombocyte Abnormalities 

Clinically Relevant Classification Principle for Anemias: 

Mean Erythrocyte Hemoglobin Content (MCH) 

In current diagnostic practice, erythrocyte count and hemoglobin content 

(grams per 100 ml) in whole blood are determined synchronously. This allows 

calculation of the hemoglobin content per individual erythrocyte 

(mean corpuscular hemoglobin, MCH) using the following simple formula 

(p. 10): 

Hb (g/dl) · 10 

Ery (10 6 /µl) 

The mean cell volume, hematocrit, MCH, and erythrocyte size can be used 

for various calculations (Table 22; methods p. 10, normal values Table 2, 

p. 12). Despite this multiplicity of possible measures, however, in routine 

diagnostic practice the differential diagnosis in cases of low Hb concentration 

or low erythrocyte counts relies above all on the MCH, and most 

forms of anemia can safely be classified by reference to the normal data 

range of 26–32 pg Hb/cell (1.61–1.99 fmol/cell) as normochromic (within 

the normal range), hypochromic (below the), or hyperchromic (above the 

norm). The reticulocyte count (p. 11) provides important additional 

pathophysiological information. Anemias with increased erythrocyte production 

(hyper-regenerative anemias) suggest a high reticulocyte count, 

while anemias with diminished erythrocyte production (hyporegenerative 

anemias) have low reticulocyte counts (Table 22). 

It should be noted that hyporegenerative anemias due to iron or vitamin 

deficiency can rapidly display hyper-regeneration activity after 

only a short course of treatment with iron or vitamin supplements (up to 

the desirable “reticulocyte crisis”). 

The practical classification of anemia starts with the MCH: 

— 26–32 pg = normochromic 

— Less than 26 pg = hypochromic 

— More than 32 pg = hyperchromic 

Hypochromic Anemias 

Iron Deficiency Anemia 

Most anemias are hypochromic. Their usual cause is iron deficiency from 

various causes (Fig. 44). To distinguish quickly between real iron deficiency 

and an iron distribution disorder, iron and ferritin levels should be 

determined. 



Insufficient iron absorption: 

● Lower than normal acidity, no 

acidity, stomach resection, 

accelerated passage from 

stomach to intestines 

● Substances that inhibit absorption 

of iron, such as citric 

acids and lactic acids, mucus and 

similar materials 

● Substances that facilitate iron 

absorption are missing 

(e.g. vitamin C) 

Insufficient iron 

supplementation: 

● Iron-deficient diet 

● In newborns: insufficient 

iron transfer from the 

mother during gravidity 

Endogenous redistribution: 

● Tumors, infections, lung 

hemosiderosis 

Iron deficiency: 


129 

Chronic bleeding and pathological 

loss of iron in the following diseases: 

● Disorders of the stomach and 

intestines (positive benzidine 

test) 

● Diseases of the urethra 

(hematuria!) 

● Diseases of the female reproductive 

cycle (menorrhagia, 

metrorrhagia) 

Increased iron requirement: 

● Growth/maturation 

● Increased production of the 

new blood cells 

Physiological iron loss 

in females: 

● Menses 

● Lactation 

● Pregnancy 

● Fatigue, koilonychia, infectious angle 

(angulus infectiosus oris), Plummer- 

Vinson syndrome, possibly “iron 

deficiency fever” 

● Anemia 

● Hypochromy, ring-shaped erythrocytes 

● Light serum, deficient in color 

components 

● Serum iron very reduced 

Fig. 44 The most important reasons for iron deficiency (according to 

Begemann) 



130 

Table 22 Diagnostic findings and work-up for the most important disorders of 

the red cell series 

Clinical 

findings 

Fatigue, 

pallor 

(dysphagia) 

Possibly 

fever, weight 

loss 

Diffuse 

symptoms 

Hb MCH Erythrocytemorphology 

Ring-shaped 

erythrocytes, 

anisocytosis 

Anisocytosis, 

poikilocytosis 

/n/ All sizes, 

dimorphic 

Reticulocytes 

Leukocytes 

Segmented 

nuclei 

(%) 

Lymphocytes 

(%) 

Other cells Thrombocytes 

n n n - n/ 

n/ n n Possibly 

eosinophils 

 

monocytes 

left shift 

n 

n/ n n - n/ 

Acute 

hemorrhage 

n n n n () () - n// 

Subjaundice n n or pathol., n/ n n Possibly nor- 

possibly 

spherocytes 

moblasts 

Spleen Target cells n n n Possibly normoblasts 

Paller n n Possibly 

possibly 

infections 

and bleeding 

tendency 

monocytes 

Pallor 

possibly 

alcohol history 

Plethora, 

possibly 

spleen 


Macrocytes, 

megalocytes 

n/ 

Possibly 

hypersegmented 

granulocytes, 

possibly normoblasts 

/n 

n n n n/ n n - n/ 

Acute bleed- 

ing tendency 

n n () n n n - 

Diagnostic steps proceed from left to right. ❘ The next step is usually unnecessary; : . the next 

step is optional; the next step is obligatory. n = normal value, = lower than normal, = ele- 

vated, ( ) = test not relevant, BSG = erythrocyte sedimentation rate. 



n

BSG Electrophoresis 

Iron Ferritin 

and 

others 

n n Ferritin 

 

? α2 

γ 

Ferritin 

n/ 

Transferrin 

Tentative 

diagnosis 

Iron deficiency 

anemia 

Evidence/ 

further diagnostics 

Determine 

source of bleeding; 

check iron 

absorption 

Acquired/sec- Search for 

ondary anemia trigger 

(infectious/ 

toxic, paraneoplastic) 

n n n/ Sideroachrestic 

anemia, 

myelodysplasia 

n n n/ – n/ Anemia due to 

hemorrhaging 

n n n Haptoglobulin 

 

n n n Haptoglobulin 

 

(n/) Hemolytic 

anemia 

Especially: 

thalassemia 

n /(n) n/ (/n) Aplastic anemia 

or bone 

marrow carcinosia 

n n n/ Vitamin 

B12 

folic acid 

 

() Megaloblastic 

anemia 

Search for 

source and 

reason for 

hemorrhages 

Osmotic 

resistance, 

Coombs test, 

Hb electrophoresis 

and 

further tests 

Search for trigger 

or tumor 

Gastroscopy, 

determination 

of antibodies, 

possibly 

Schilling test 

n/ n Polyeythemia, ALP, progress- 

DD: hypergamionmaglobulinemia n n duration 

of 

hemorrhaging 

 

PTT n 

– Thrombocytopenic 

purpura 

(ITP) 


Search for triggers, 

possibly 

also for antibodies 

. 

Bone marrow Ref. 

page 

Erythropoiesis 

sideroblasts , 

iron in macrophages 

 

Erythropoiesis , 

sideroblasts 

iron in macrophages 

131 

p. 132 

p. 134 

. 

Erythropoiesis , p. 106 

ring sideroblasts 

present 

. 

(Erythropoiesis 

) 

p. 140 

(Erythropoiesis p. 140 

, right shift) 

increased storage 

of iron 

p. 138 

Hypoplasia of all 

cell series, or carcinoma 

cells 

Erythropoietic 

megaloblasts 

p. 146, 

148, 150 

p. 152 

. 

Erythropoiesis p. 162 

Elevated megakaryocyte 

count 



p. 166

132 


Table 23 Normal ranges for physiological iron and its transport proteins 

Old units SI units 

Serum iron 

Newborns 150–200µg/dl 27–36µmol/l 

Adults 

Female 60–140µg/dl 11–25µmol/l 

Male 80–150µg/dl 14–27µmol/l 

TIBC 300–350µg/dl 54–63µmol/l 

Transferrin 250–450µg/dl 2.5–4.5 g/l 

Serum ferritin 30–300µg/l 

(15–160µg/l premenopausal) 

TIBC = Total iron binding capacity. 

This usually renders determination of transferrin and total iron binding 

capacity (TIBC) unnecessary. If samples are being sent away to a laboratory, 

it is preferable to send serum produced by low-speed centrifugation, 

since the erythrocytes in whole blood can become mechanically damaged 

during shipment and may then release iron. Table 23 shows the variation 

of serum iron values according to gender and age. 

It is important to note that acute blood loss causes normochromic anemia. 

Only chronic bleeding or earlier serious acute blood loss leads to iron 

deficiency manifested as hypochromic anemia. 

Iron Deficiency and Blood Cell Analysis Focusing on the erythrocyte morphology 

is the quickest and most efficient way to investigate hypochromic 

anemia when the serum iron has dropped below normal values. In hypochromic 

anemia with iron and hemoglobin deficiency (whether due to insufficient 

iron intake or an increased physiological iron requirement), 

erythrocyte size and shape does not usually vary much (see Fig. 45). Only in 

advanced anemias (from approx. 11 g/dl, equivalent to 6.27 mmol/l Hb) 

are relatively small erythrocytes (microcytes) with reduced MCV and 

MCH and grayish stained basophilic erythrocytes (polychromatic erythrocytes) 

seen, indicating inadequate hemoglobin content. Cells with the 

appearance of relatively large polychromatic erythrocytes are reticulocytes. 

The details of their morphology can be seen after supravital staining 

(p. 141). A few target cells (p. 139) will be seen in conditions of severe iron 

deficiency. 

In severe hemoglobin deficiency ( 8 g/dl, equivalent to 4.96 mmol/l) 

the residual hemoglobin is found mostly at the peripheral edge of the 

erythrocyte, giving the appearance of a ring-shaped erythrocyte. 



a 

c 

Small, hemoglobin-poor erythrocytes indicate iron deficiency 

Fig. 45 Iron deficiency anemia. a and b Erythrocyte morphology in iron deficiency 

anemia: ring-shaped erythrocytes (1), microcytes (2) faintly visible target cells 

(3), and a lymphocyte (4) for size comparison. Normal-sized erythrocytes (5) after 

transfusion. c Bone marrow cytology in iron deficiency anemia shows only increased 

hematopoiesis and left shift to basophilic erythroblasts (1). d Absence of 

iron deposits after iron staining (Prussian blue reaction). Megakaryocyte (1). 



133 

b 

d

134 Erythrocyte and Thrombocyte Abnormalities 

Hypochromic Infectious or Toxic Anemia 

(Secondary Anemia) 

Among the various causes of lack of iron for erythropoiesis (see Fig. 44, 

p. 129), a special situation is represented by the internal iron shift caused 

by “iron pull” of the reticuloendothelial system (RES) during infections, 

toxic processes, autoimmune diseases, and tumors. Since this anemia results 

from another disorder, it is also called secondary anemia. The MCH is 

hypochromic, or in rare instances, normochromic, and therefore erythrocyte 

morphology is particularly important to diagnosis. In contrast to exogenous 

iron deficiency anemias, the following phenomena are often observed, 

depending on the severity of the underlying condition: 

➤ Anisocytosis, i.e., strong variations in the size of the erythrocytes, beyond 

the normal distribution. The result is that in almost every field 

view, some erythrocytes are either half the size or twice the size of their 

neighbors. 

➤ Poikilocytosis, i.e., variations in the shape of the erythrocytes. In addition 

to the normal round shape, numbers of oval, or pear, or tear shaped 

cells are seen. 

➤ Polychromophilia, the third phenomenon in this series of nonspecific 

indicators of disturbed erythrocyte maturation, refers to light grayblue 

staining of the erythrocytes, indicating severely diminished 

hemoglobin content of these immature cells. 

➤ Basophilic cytoplasmic stippling in erythrocytes is a sign of irregular regeneration 

and often occurs nonspecifically in secondary anemia. 

The reticulocyte count is usually reduced in infectious or toxic anemia, unless 

there is concomitant hemolysis or acute blood loss. 

Bone marrow analysis in secondary anemia usually shows reduced 

erythropoiesis and granulopoiesis with a spectrum of immature cells (“infectious/toxic 

bone marrow”). The information is so nonspecific that usually 

bone marrow aspiration is not performed. So long as all other laboratory 

methods are employed, bone marrow cytology is very rarely needed 

in cases of hypochromic anemia. 



Hypochromic erythrocytes of very variable morphology indicate 

secondary anemia, usually in cases of infectious disease or 

tumor 

a b 

Fig. 46 Secondary anemia. a and b Erythrocyte morphology in secondary hypochromic 

anemia: the erythrocytes vary greatly in size (anisocytosis) and shape (1) 

(poikilocytosis), and show basophilic stippling (2). Burr cell (3), which has no specific 

diagnostic significance. Occasionally, the erythrocytes stain a soft gray–blue 

(4) (polychromasia). c Bone marrow cell overview in secondary anemia. Cell 

counts in the white cell series are elevated (promyelocytes = 1), eosinophils (2), 

and plasma cells (3); erythropoiesis is reduced (4). 

135 



c


Bone Marrow Cytology in the Diagnosis of Hypochromic 

Anemias 

So long as all other laboratory methods are employed, bone marrow cytology 

is very rarely needed in cases of hypochromic anemia. 

Bone marrow cytology is rarely strictly indicated after all other available 

diagnostic methods have been exhausted (Table 22, p. 130). However, in 

doubtful cases it can usually at least help to rule out malignant disease. 

In iron deficiency anemias of the most various etiologies, erythropoiesis 

is stimulated in a compensatory fashion, and the distribution of the 

markers shows the expected increase in red cell precursors. The erythropoiesis 

to granulopoiesis ratio increases in favor of erythropoiesis from 

1 :3 to 1 :2, but rarely further. The red cell series shows a left shift, i.e., 

there are more immature red cell precursors (erythroblasts and proerythroblasts) 

(for normal values, see Table 4). Usually, these red cell precursors 

do not show any clearly atypical morphology, but the cytoplasm is basophilic 

even in normoblasts, according with the poor hemoglobinization. 

Iron staining of the bone marrow shows no sideroblasts (normoblasts containing 

iron granules), or only very few ( 10%, norm 30–40%). A constant 

finding in anemia stemming from exogenous iron deficiency is absence of 

iron in the macrophages of the bone marrow reticulum. 

Megakaryocyte counts are almost always increased in iron deficiency 

due to chronic hemorrhaging, but can also show increased proliferation in 

iron deficiency from other causes (which can lead to increased thrombocyte 

counts in states of iron deficiency). 

In infectious or toxic (secondary) anemia, unlike exogenous iron deficiency 

anemia, erythropoiesis tends to be somewhat suppressed. There is 

no left shift and no specific anomalies are present. Granulopoiesis predominates 

and often shows nonspecific “stress phenomena” and a dissociation 

of nuclear and cytoplasmic maturation (e.g., cytoplasm that is still 

basophilic with promyelocytic granules in mature, banded myelocyte nuclei). 

Depending on the trigger of the anemia, the monocyte, lymphocyte, or 

plasma cell counts are often moderately increased, and megakaryocyte 

counts are occasionally slightly elevated. The important indicator is iron 

staining of the bone marrow. The “iron pull” of the RES leads to intensive 

iron storage in macrophages, while the red cell precursors are almost ironfree. 

However, combinations do exist, when a pre-existing iron deficiency 

means that the iron depositories are empty even in an infectious or toxic 

process. Moreover, not every secondary anemia is hypochromic. Where 

there is concomitant alcoholism or vitamin deficiency, secondary anemia 

may be normochromic or hyperchromic. 




Hypochromic Sideroachrestic Anemias 

(Sometimes Normochromic or Hyperchromic) 

137 

In a sideroachrestic anemia existing iron cannot be utilized (achrestic 

= useless). This is a suspected diagnosis when serum iron levels are 

raised or in the high normal range, and when the erythrocytes show strong 

anisocytosis, poikilocytosis (with reduced average MCV), polychromophilia, 

and in some cases also basophilic stippling (Fig. 46). This suspicion can be 

further illuminated by bone marrow analysis. Unlike in infectious/toxic 

anemias, the red cell series is well represented. Iron staining of the bone 

marrow is the decisive diagnostic test, causing the iron-containing red 

precursor cells (sideroblasts) to stand out (hence the term “sideroblastic 

anemia.”) The iron precipitates often collect in a ring around the nucleus 

(“ringed sideroblasts”). 

By far the majority of the “idiopathic sideroachrestic anemias,” as they 

used to be called, are myelodysplasias (see p. 106). Only a few of them appear 

to be hereditary or have exogenous triggers (alcoholism, lead poisoning). 




Hypochromic Anemia with Hemolysis 

Thalassemias 

A special form of hypochromic anemia mostly affecting patients of Mediterranean 

descent presents with normal erythrocyte count, decreased 

MCH, and clinical splenomegaly. The smear displays erythrocytes with 

central hemoglobin islands (target cells). These cells do not necessarily 

predominate in the CBC: the most revealing field views show at most 50% 

target cells in addition to clear anisocytosis and frequent basophilic stippling. 

Occasional normoblasts give a general indication of increased erythropoiesis. 

Although target cells are also nonspecific, since they can occur 

in such conditions as severe iron deficiency or obstructive jaundice, this 

overall picture should prompt hemoglobin electrophoresis. The sample 

consists of ACD-stabilized blood at 1 :10 dilution. A significant increase in 

the HbA2 fraction confirms a diagnosis of thalassemia minor, the heterozygous 

form of the disease. Thalassemia major, the homozygous variant, is 

far rarer and more serious. In this form of the disease, in addition to the 

target cells, the CBC shows a marked increase in red precursor cells. Hbelectrophoresis 

shows a predominance of HbF (the other hemolytic anemias 

are usually normochromic, see p. 140). 



Hypochromic anemia without iron deficiency, sometimes with 

target cells, suggests thalassemia 

a b 

Fig. 47 Thalassemia. a Thalassemia minor: often no target cells, but an increase 

in the number of small erythrocytes (shown here in comparison with a lymphocyte), 

so that sometimes there is no anemia. b More advanced thalassemia minor: 

strong anisocytosis and poikilocytosis (1), basophilic stippling (2), and sporadic 

target cells (3). c Thalassemia major: erythroblasts (1), target cell (2), polychromatic 

erythrocytes (3), and Howell–Jolly bodies (4) (in a case of functional asplenia). 

Lymphocyte (5) and granulocyte (6). 



139 

c


Normochromic Anemias 

Anemias where red cell hemoglobinization is normal (26–32 pg/dl, equivalent 

to 1.61–1.99 fmol/l) and average MCVs are normal (77–100 fl) can 

broadly be explained by three mechanisms: a) acute blood loss with sufficient 

metabolic reserves remaining; b) elevated cell turnover in which iron 

is reused as soon as it becomes free, so that hypochromia does not arise 

(this is typical of almost all hemolytic anemias except thalassemias; see 

p. 138); and c) suppression of cell production under conditions of normal 

iron supply (this is the group of hypoplastic–aplastic anemias, which have 

a variety of causes). 

— In cases of acute blood loss: clinical findings, occult blood? 

— In hemolytic cases: reticulocytes , haptoglobin , possibly bilirubin 

. 

— In bone marrow suppression: e.g. aplastic anemia, reticulocytes . 

Normochromic Hemolytic Anemias 

Hemolytic anemias result from a shortened erythrocyte life span with insufficient 

compensation from increased erythrocyte production (Table 

24). 

Usually, hematopoiesis in the bone marrow is increased in compensation, 

and, depending on the course of the disease, may make up for the accelerated 

cell degradation for all or some of the time by recycling the iron as 

it becomes free. 

Accordingly, counts of the young, newly emerged erythrocytes (reticulocytes) 

are always raised, and usually sporadic normoblasts are found. Anemia 

proper often becomes apparent only in a “crisis” with acute, accelerated 

cell degradation, and reticulocyte counts increased up to more than 

500%. 

A common cellular phenomenon after extended duration of hemolytic 

anemia is the manifestation of macrocytic hypochromic disorders (p. 150), 

because the chronic elevation of hematopoietic activity can exhaust the 

endogenous folic acid reserves (pernicious anemia). 

Bone marrow analysis shows both relative and absolute increases in 

erythropoietic activity: among the red cell precursors, in acute severe 

hemolysis the more immature forms often predominate more than in normal 

bone marrow, and in chronic hemolysis the maturer forms do 

(orthochromatic normoblasts). In addition, the normoblasts in hemolytic 

bone marrow often are markedly clustered (Fig. 48), whereas in normal 

bone marrow they are more evenly dispersed (Fig. 18). 



Consistently elevated “young” erythrocytes (reticulocytes) suggest 

hemolysis 

a b 

Fig. 48 Hemolytic anemia. a and b Newly formed erythrocytes appear as large, 

polychromatic erythrocytes (1) after Pappenheim staining (a); supravital staining 

(b) reveals spot-like precipitates (reticulocyte = 2). Thrombocyte (3). c Bone marrow 

cells in hemolytic anemia at low magnification: increased hematopoiesis with 

cell clusters. Orthochromatic erythroblasts predominate. A basophilic erythroblast 

shows loosened nuclear structure (arrow), a sign of secondary folic acid deficiency. 



141 

c

142 

Table 24 Causes of the most common hemolytic anemias 

Special morphological 

features of erythrocytes 

Causes within the erythrocytes (corpuscular hemolyses) 

➤ Hereditary 

Membrane abnormalities 

– Spherocytosis (see p. 144) 

– Elliptocytosis 

Hemoglobin abnormalities 

– Thalassemia (see p. 138) 

– Sickle cell anemia (see 

p. 144) 

– Other rare hemoglobin- 

related disorders 

Enzyme defects 

– Glucose-6-phosphate 

dehydrogenase 

– Pyruvate kinase and 

many others 

➤ Acquired 

Paroxysmal nocturnal 

hemoglobinuria 

– Small spherocytes 

– Elliptocytes 

– Target cells 

– Sickle cells 

– Possibly Heinz bodies 

– Macrocytes 

Zieve syndrome – Foam cells in the bone 

marrow 

Further advanced 

diagnostics 

Osmotic resistance 

Hemoglobin electrophoresis 

Enzyme tests 

Sucrose hemolysis 

test, absence of CD 55 

(DAF) and CD 59 

MIRL (membrane 

inhibitor of reactive 

lysis) 

Causes outside the erythrocytes (extracorpuscular hemolyses) 

➤ Biosynthesis of antibodies 

Isoantibodies (fetal erythro- 

Rh serology 

blastosis, transfusion events) 

Warm autoantibodies Coombs test 

Cold autoantibodies 

Chemical-allergic antibodies 

(e. g., cephalosporin, methyldopa) 

– Autoagglutination Coombs test, 

Cold agglutination 

titer 

➤ Physical or chemical noxae 

(e. g., after burns, heart valve 

replacement; heavy metal 

exposure, animal- or plantderived 

poisons) 

– Partially Heinz bodies 

➤ Microangiopathic hemolysis in 

hemolytic-uremic syndrome, 

thrombotic-thrombocytopenic 

purpura, bone marrow carcinoses 

➤ Infection-related noxae (e. g. 

influenza, salmonella infection, 

malaria) 


➤ Hypersplenism, e. g. lymphatic 

system disease, infections with 

splenomegaly, portal hypertension 

– Schizocytes, fragmentocytes 

(see p. 143) 

– For malaria pathogen 

(see p. 158) 

Thrombocytes 

Liver, kidney 

Demonstration of 

pathogen 

Cause of 

splenomegaly 



a 

Distribution pattern and shape of erythrocytes can be relevant in 

the diagnosis of hemolysis 

b c 

Fig. 49 Autoagglutination and fragmentocytes. a Clumps of erythrocytes. If this 

is the picture in all regions of the smear, an artifact is unlikely and serogenic (auto)agglutination 

should be suspected (in this case due to cryoagglutinins in mycoplasmic 

pneumonia). Thrombocytes are found between the agglutinated erythrocytes. 

b and c Conspicuous half-moon and egg-shell-shaped erythrocytes: fragmentocytosis 

in microangiopathic hemolytic anemia. Fragmentocytes (1), target 

cell (2), and echinocytes (3) (this last has no diagnostic relevance). 



143


Cytomorphological Anemias with Erythrocyte 

Anomalies 

Microspherocytosis This corpuscular form of hemolysis is characterized 

by dominant genetic transmission, splenomegaly, and a long uneventful 

course with occasional hemolytic crises. Blood analysis shows erythrocytes 

which appear strikingly small in comparison with leukocytes. The 

central light area is absent or only faintly visible, since they are spherical 

in cross-section rather than barbell-shaped. The abnormal size distribution 

can be measured in two dimensions and plotted using Price–Jones 

charts. Close observation of the morphology in the smear (Fig. 50) is particularly 

important, because automated blood analyzers will determine 

a normal cell volume. The extremely reduced osmotic resistance of the 

erythrocytes (in the NaCl dilution series) is diagnostic. Coombs test is 

negative. 

Stomatocytosis is an extremely rare hereditary condition. Stomatocytes 

are red cells with a median streak of pallor, giving the cells a “fish mouth” 

appearance. A few stomatocytes may be found in hepatic disease. 

Hemoglobinopathies (see also thalassemia, p. 138). Target cells are 

frequently present (Fig. 47). 

In addition to target cells, smears from patients with sickle cell anemia 

may show a few sickle-shaped erythrocytes, but more usually these only 

appear under conditions of oxygen deprivation (Fig. 50). (This can be 

achieved by covering a fresh blood droplet with a cover glass; a droplet of 

2% Na2S2O4 may be added). Sickle cell anemia is a dominant autosomal recessive 

hemoglobinopathy and is diagnosed by demonstrating the HbS 

band in Hb-electrophoresis. Homozygous patients with sickle cell anemia 

always suffer from chronic normocytic hemolysis. If provoked by oxygen 

deficiency or infections, severe crises may occur with clogging of the microvasculature 

by aggregates of malformed erythrocytes. Patients who are 

heterozygous for sickle cell anemia have the sickle cell trait but do not display 

the disease or its symptoms. These can, however, be triggered by very 

low oxygen tension. Sickle cell anemia is quite often combined with other 

hemoglobinopathies, such as thalassemia. 

Schistocytosis (Fragmentocytosis) If, in acquired hemolytic anemia, some 

of the erythrocytes are fragmented and have various irregular shapes 

(eggshell, helmet, triangle, or crescent; Fig. 49), this may be an indication 

of changes in the capillary system (microangiopathy), or else of disseminated 

intravascular coagulopathy (DIC). Microangiopathic hemolytic anemias 

develop in the course of thrombotic thrombocytopenic purpura (TTP, 

Moschcowitz disease) and its related syndromes: in children (hemolytic 

uremic syndrome, HUS); in pregnant women (HELLP syndrome); or in 

patients with bone marrow metastases from solid tumors. 



Conspicuous erythrocyte morphology in anemia: microspherocytosis 

and sickle cell anemia 

a b 

c d 

Fig. 50 Microspherocytes and sickle cells. All erythrocytes are strikingly small in 

comparison with lymphocytes (1) and lack a lighter center: these are microspherocytes 

(diameter 6 µm). Polychromatic erythrocyte (2). b Erythrocytes with an 

elongated rather than round lighter center: these are stomatocytes, which are rarely 

the cause of anemia. c Native sickle cells (1) are found only in homozygous 

sickle cell anemia, otherwise only target cells (2) are present. d Sickle cell test under 

reduced oxygen tension: almost all erythrocytes appear as sickle cells in the 

homozygous case presented here. 

145 




Normochromic Renal Anemia 

(Sometimes Hypochromic or Hyperchromic) 

Normochromic anemia should also suggest the possibility of renal insufficiency, 

which will always lead to anemia within a few weeks. In cases of 

chronic renal insufficiency it is always present and may reach Hb values as 

low as 6 g/dl. The anemia is caused by changes in the synthesis of erythropoietin, 

the hormone regulating erythropoiesis; measurement of serum 

erythropoietin is an important diagnostic tool. Erythrocyte life span is also 

slightly reduced. 

Apart from poikilocytosis, the blood cells are morphologically unremarkable. 

The reticulocyte counts often remain normal. The bone marrow 

does not show any significant characteristic changes, and therefore serves 

no diagnostic purpose in this situation. 

Anemias due to renal insufficiency are usually normochromic, but hypochromic 

or hyperchromic forms do occur. Hypochromic anemia is an indicator 

of the reactive process that has led to the renal insufficiency (e.g., 

pyelonephritis and glomerulonephritis), resulting in secondary hypochromic 

anemia. In addition, dialysis patients often develop iron deficiency. 

Chronic renal insufficiency can lead to folic acid deficiency, and 

dialysis therapy will reinforce this, explaining why hyperchromic anemias 

also occur in kidney disease. 

Bone Marrow Aplasia 

Pure Red Cell Aplasia (PRCA, Erythroblastopenia) 

Erythroblastopenia in the sense of a purely aplastic condition in the red 

cell series is extremely rare. Diamond–Blackfan anemia (congenital hypoplastic 

anemia) is the congenital form of this disease. Acquired acute, transient 

infections in adults and children are usually caused by virus infections 

(parvovirus B19). Chronic acquired erythroblastophthisis is 

frequently associated with thymoma and has an autoimmune etiology. 

Anemia in pure erythroblastophthisis is normochromic without significant 

changes in the CBC for white cells and thrombocytes. Naturally, the 

reticulocyte count is extremely low, close to zero. 

In all these anemias, the bone marrow shows well-developed granulopoiesis 

and megakaryopoiesis, but erythropoiesis is (more or less) entirely 

lacking. 



a 

c 

Unexplained decrease in cell counts for one or more lines: the 

bone marrow smear may show various forms of aplasia 

Fig. 51 Forms of bone marrow aplasia. a Bone marrow cytology in erythroblastopenia: 

only activated cells of the granulopoietic series are present. The megakaryopoiesis 

(not shown here) show no abnormalities. b Bone marrow aplasia: 

hematopoiesis is completely absent: only adipocytes and stroma cells are seen. 

c Giant erythroblast (arrow) in the bone marrow in acute parvovirus B19 infection. 

d Conspicuous binuclear erythroblasts in the bone marrow of a patient with congenital 

dyserythropoietic anemia (type II CDA). 



147 

b 

d

148 


The differential diagnosis in this context relates to very rare congenital 

dyserythropoietic anemias (CDA). These anemias manifest mostly in 

childhood or youth and may be normocytic or macrocytic. The bone marrow 

shows increased erythropoiesis with multinucleated erythroblasts, 

nuclear fragmentation, and cytoplasmic bridges. There are three types 

(type II carries the so-called HEMPAS antigen: hereditary multinuclearity 

with positive acidified serum lysis test). 

Aplasias of All Bone Marrow Series (Panmyelopathy, 

Panmyelophthisis, Aplastic Anemia) 

A reduction in erythrocyte, granulocyte, and thrombocyte cell counts in 

these series, which may progress to zero, is far more common than pure 

erythroblastopenia and is always acquired (except in the rare pediatric 

Fanconi syndrome with obvious deformities). 

Pathologically, this life-threatening disease is a result of damage to the 

hematopoietic stem cells, often by chemical toxins or, occasionally, viral 

infection. An autoimmune response of the T-lymphocytes also seems to 

play a role. 

The term “panmyelopathy” is synonymous with “aplastic anemia” in 

the broader sense and with “panmyelophthisis.” 

The CBCs show the rapid progression of normochromic anemia and 

greatly reduced reticulocyte counts. Granulocyte counts gradually 

dwindle to zero, followed by the monocytes. Thrombocytes are usually 

also quite severely affected. 

The remaining blood cells in all series appear normal, although naturally, 

given the presence of the noxious agents or intercurrent infections, 

they often show reactive changes (e.g., toxic granulations). The bone marrow 

aspirate for cytological analysis is often notable for poor yield of 

material, although a completely empty aspirate (dry tap) is rare. 

The material obtained yields unfamiliar images in a smear (Fig. 51). 

Frequently, strings and patches of reticular (stroma) cells from the bone 

marrow predominate, which normally are barely noticed in an aspirate. 

There are usually no signs of phagocytosis. Aside from the reticular cells, 

there are isolated lymphocytes, plasma cells, tissue basophils, and macrophages. 

Depending on the stage in the aplastic process, there may be residual 

hematopoietic cells. In some instances, the whole disease process is 

focal. For this reason, bone marrow histology must be performed 

whenever the cytological findings are insufficient or dubious in cases of 

tricytopenia of unknown cause. 



Table 25 Substances, suspected or proven to cause panmyelopathy 

Analgesics, antirheumatic 

drugs 


Phenylbutazone, oxyphenbutazone, other 

nonsteroidal antirheumatic drugs, gold 

preparations, penicillamine 

Antibiotics Chloramphenicol, sulfonamide 

Anticonvulsive drugs Hydantoin 

Thyrostatic drugs Carbimazole/methimazole 

Sedatives Phenothiazines 

Other medications Cimetidine, tolbutamide 

Insecticides Hexachlorcyclohexane and other chlorinated 

hydrocarbons 

Solvents Benzene 

Viruses z. B. Hepatitis, CMV 

149 

Differential Diagnosis versus Reduction in Cell Counts in Several Series 

(Bicytopenia or Tricytopenia): 

➤ After thorough analysis, most cytopenias with hyperplasia of the bone 

marrow have to be defined as myelodysplasias (p. 106), unless they are 

caused by accelerated cell degeneration (e.g., in hypersplenism). 

➤ Cytopenia with bone marrow fibrosis points to myeloproliferative-type 

diseases (p. 114) or results from direct toxic or inflammatory agents. 

➤ Cytopenia can of course also occur after bone marrow infiltration by 

malignant cells (carcinoma, sarcoma), which will not be contained in 

every bone marrow aspirate. This is why, when the diagnosis is uncertain, 

histological analysis should always be carried out. 

➤ Cytopenia can also result from B12 or folic acid deficiency (but note the 

possibility of hyperchromic anemia, p. 152). 

➤ Another cause of cytopenia is expansion of malignant hematopoietic 

cells in the bone marrow. This is easily overlooked if the malignant cells 

do not appear in the bloodstream, as in plasmacytoma, lymphadenoma, 

and aleukemic leukemia (leukemia without peripheral blasts). 

➤ Cytopenia also develops of course after high-dose radiation or 

chemotherapy. In such cases it is not so much the CBC or bone marrow 

analysis as the exposure history that will allow the condition to be distinguished 

from the panmyelopathies described above. 

➤ Cytopenia caused by panmyelopathy mechanisms (see preceding text; 

triggers shown in Table 25). 



150 


In unexplained anemia, thrombocytopenia, or leukocytopenia, any 

possible triggers (Table 25) must be discontinued or avoided. Panmyelophthisis 

or aplastic anemia is an acute disease that can only be overcome 

with aggressive treatment (glucocorticoids, cyclosporin, antilymphocyte 

globulin). 

Bone Marrow Carcinosis and Other Space-Occupying 

Processes 

Anemia resulting from bone marrow infiltration by growing, spaceoccupying 

tumor metastases can in principle be normochromic. However, 

under the indirect influence of the underlying disease, it tends more often 

to be hypochromic (secondary anemia). 

Normoblasts in the differential blood analysis (Fig. 9 a, p. 33) particularly 

suggest the possibility of bone marrow carcinosis, because their presence 

implies destruction of the bone marrow–blood barrier. Usually, bone marrow 

carcinosis leads eventually to lower counts in other cell series, 

especially thrombocytes. 

Bone metastases from malignant tumors rarely affect the bone marrow 

and hematopoiesis, and if they do, it is usually late. The most common 

metastases in bone marrow derive from small-cell bronchial carcinoma 

and breast cancer. 

In the differential diagnosis, the effects of direct bone marrow infiltration 

must be distinguished from phenomena caused by microangiopathic 

hemolytic anemia (MHA) in the presence of tumor (p. 144). Carcinosis and 

MHA may of course coexist. 

Bone marrow cytology in these situations tends to reveal a generally 

decreased density of hematopoietic cells and signs of reactive marrow as 

seen in secondary anemia (p. 134). Only in a few field views—often at the 

edge of the smear—will one occasionally encounter atypical cell elements 

which cannot be assigned with certainty to any of the hematopoietic blast 

families. The critical feature is their close arrangement in clusters. These 

atypical cells are at least as large as myeloblasts or proerythroblasts (e.g., 

in small-cell bronchial carcinoma), usually considerably larger. Tumor 

type cannot be diagnosed with certainty (except, e.g., melanoma). Bone 

marrow histology and possibly immunohistology tests must be performed 

if there is any doubt, or in the case of negative cytological findings 

or dry tap, since the clustered, focal character of metastases naturally 

means that they may not be obtained in every aspirate. 



Thrombocytopenia with leukocytosis and erythroblasts in the 

peripheral blood: consider bone marrow carcinosis 

a b 

Fig. 52 Bone marrow carcinosis. a and b Bone marrow smear at low magnification 

showing islands of infiltration by a homogeneous cell type (a), or, alternatively, 

by apparently different cell types which do, however, all display identical chromatin 

structure and cytoplasm: bone marrow carcinosis in breast carcinoma (a) or 

bronchial non-small-cell carcinoma (b). c Island of dedifferentiated cells in the 

bone marrow which cannot be assigned to any of the hematopoietic lineages: 

bone marrow carcinosis (here in a case of embryonal testicular cancer). 



151 

c

152 


Hyperchromic Anemias 

In patients with clear signs of anemia, e.g., a “sickly pallor,” atrophic lingual 

mucosa, and sometimes also neurological signs of bathyanesthesia 

(loss of deep sensibility), even just a cursory examination of the blood 

smear may indicate the diagnosis. Marked poikilocytosis and anisocytosis 

are seen, and the large size of the erythrocytes is particularly conspicuous 

in comparison with the lymphocytes, whose diameter they exceed (megalocytes). 

These are the hallmarks of macrocytic, and, with respect to bone 

marrow cells, usually also megaloblastic anemia, with a mean cell diameter 

greater than 8 µm and a cell volume (MCV) usually greater than 

100 µm 3 . Mean cell Hb content (MCH) is more than 36 pg (1.99 fmol) and 

thus indicates hyperchromic anemia. 

Only when there is severe pre-existing concomitant iron deficiency is a 

combination of macrocytic cells and hypochromic MCH possible (“dimorphic 

anemia”). 

Table 26 Most common causes of hyperchromic anemias 

Vitamin-B12 deficiency Folic acid deficiency 

Nutritional deficits, e. g. Nutritional deficits 

– Goat milk 

– Chronic abuse of alcohol 

– Vegetarian diet 

– Alcoholism 

Impaired absorption Impaired absorption 

– Genuine pernicious anemia 

– E.g., sprue (psilosis) 

– Status after gastrectomy 

Increased requirement 

– Ileum resection 

– Crohn disease 

– Pregnancy 

– Celiac disease, sprue (psilosis) 

– Hemolytic anemia 

– Intestinal diverticulosis 

Interference/antagonism 

– Insufficiency of the exocrine pancreas – Phenylhydantoin 

– Fish tapeworm 

– Cytostatic antimetabolic drugs 

– Trimethoprim (antibacterial 

combination drug) 

– Oral contrazeptives 

– Antidepressants 

– Alcohol 

Although other rare causes exist (Table 26), almost all patients with hyperchromic 

anemia suffer from vitamin B12 and/or folic acid deficiency. 

Since a deficiency of these essential metabolic building blocks suppresses 

DNA synthesis not only in erythropoiesis, but in the other cell series as 

well, over time more or less severe pancytopenia will develop. 



a 

c 

Conspicuous large erythrocytes suggest hyperchromic macrocytic 

anemia, usually megaloblastic in the bone marrow 

Fig. 53 Hyperchromic anemia. a Marked anisocytosis. In addition to normalsized 

erythrocytes (1), macrocytes (2) and large ovoid megalocytes are seen (3). 

Hypersegmented granulocyte (4). b In hyperchromic anemia, red cell precursors 

may be released into the peripheral blood: here, a polychromatic erythroblast. c 

and d Bone marrow in megaloblastic anemia: slight (1) or marked (2) loosening 

up of the nuclear structure, in some cases with binuclearity (3). Giant forms of 

band granulocytes and metamyelocytes (4) are often present. 



153 

b 

d

154 


With hypersegmentation, i.e. 4–5 segments/nucleus, the segmented 

granulocytes show all the indications of a maturation disorder. In addition, 

the reticulocyte count is increased (but it may also be normal), and 

the iron content is elevated or normal. 

Megaloblastic anemias show the same hematological picture whether 

they are caused by folic acid deficiency or by vitamin B12 deficiency. 

Table 26 lists possible causes. It should be emphasized that “genuine” pernicious 

anemia is less common than megaloblastic anemia due to vitamin 

B12 deficiency. In pernicious anemia a stomach biopsy shows atrophic 

gastritis and usually also serum antibodies to parietal cells and intrinsic 

factor. 

Among the causes of folic acid deficiency is chronic alcoholism (with 

insufficient dietary folic acid, impaired absorption, and elevated erythrocyte 

turnover). On the other hand, many alcoholics with normal vitamin 

B12 and folic acid levels develop severe hyperchromic anemia with a 

special bone marrow morphology, obviously with a pathomechanism of 

its own (pyridoxine [B6] deficiency, among others). 

In megaloblastic anemia (Fig. 53) the cell density in the bone marrow is 

always remarkably high. Large to medium-sized blasts with round nuclei 

dominate the erythrocyte series. They are present in varying sizes, their 

chromatin is loosely arranged with a coarse “sandy” reticular structure, 

there are well-defined nucleoli, and the cytoplasm is very basophilic with 

a perinuclear lighter zone. These cells can be interpreted as proerythroblasts 

and macroblasts whose maturation has been disturbed. As these 

disturbed megaloblastic cells appear along a continuous spectrum from 

the less mature to the more mature, they are all referred to collectively as 

megaloblasts. 

In the granylocytic series, anomalies become obvious at the myelocyte 

stage; characteristic giant cells with loosely structured nuclei develop 

which may tend to be classified as myelocytes/stab cells, but which in fact 

probably are myelocytes in which the maturation process has been disturbed. 

As in peripheral blood smears, segmented granulocytes are often 

hypersegmented. Megakaryocytes also show hypersegmentation of their 

nuclei or many individual nuclei. Iron staining reveals increased number 

of iron-containing reticular cells and sideroblasts, and a few ring sideroblasts 

may develop. All these changes disappear after vitamin B12 supplementation, 

after just three days in the erythrocyte series and within 

one week in the granulocyte series. In the differential diagnosis, in relation 

to the causes listed in Table 26, the following should be highlighted: toxic 

alcohol damage (vacuolized proerythroblasts), hemolytic anemia (elevated 

reticulocyte count), myelodysplasia (for bone marrow morphology see 

Fig. 37, p. 109). 



a 

In older patients, myelodysplastic syndrome should be the first 

item in the differential diagnosis of hyperchromic anemias 

b c 

Fig. 54 Myelodysplastic syndrome (MDS) as differential diagnosis in hyperchromic 

anemia. a Strongly basophilic stippling in the cytoplasm of a macrocyte 

(in myelodysplasia). b Myeloblast with hyperchromic erythrocyte as an example 

of a myelodysplastic blood sample in the differential diagnosis versus hyperchromic 

anemia. c A high proportion of reticulocytes speaks against megaloblastic 

anemia and for hemolysis (in this case with an absence of pyruvate kinase activity). 

d Bone marrow in myelodysplasia (type RAEB), with clinical hyperchromic 

anemia. 

155 



d

156 


Erythrocyte Inclusions 

Erythrocytes normally show fairly homogeneous hemoglobinization after 

panoptic staining; only after supravital staining (p. 155) will the remains 

of their ribosomes show as substantia granulofilamentosa in the reticulocytes. 

Under certain conditions during the preparation of erythrocytes, 

aggregates of ribosomal material may be seen as basophilic stippling, also 

visible after Giemsa staining (Fig. 55 a). This is normal in fetal and infant 

blood; in adults a small degree of basophilic stippling has nonspecific diagnostic 

value, like anisocytosis indicating only a nonspecific reactive 

process. Not until a large proportion of basophilic stippled erythrocytes is 

seen concomitantly with anemia does this phenomenon have diagnostic 

significance: thalassemia, lead poisoning, and sideroblastic anemia are all 

possibilities. Errant chromosomes from the mitotic spindle are sometimes 

found in normoblasts as small spheres with a diameter of about 1 µm, 

which have remained in the erythrocyte after expulsion of the nucleus and 

lie about as unevenly distributed Howell–Jolly bodies in the cytoplasm 

(Fig. 55 b, c). Normally, these cells are quickly sequestered by the spleen. 

Always after splenectomy, rarely also in hemolytic conditions and megaloblastic 

anemia, they are observed in erythrocytes at a rate of 1‰. 

These Howell-Jolly bodies are visible after normal panoptic staining. 

Supravital staining (see reticulocyte count, p. 11) may produce a few 

globular precipitates at the cell membrane, known as Heinz bodies. They 

are a rare phenomenon and may indicate the presence of unstable 

hemoglobins in rare familial or severe toxic hemolytic conditions (p. 144). 

An ellipsoid, eosinophil-violet stained, delicately structured ring in 

erythrocytes is called a Cabot ring (Fig. 55 d). It probably consists not, as its 

form might suggest, of remnants of the nuclear membrane, but of fibers 

from the mitotic spindle. Because these ring structures are sporadically 

seen in all severe anemias, no specific conclusions can be drawn from their 

presence, but in the absence of any other rationale for severe anemia they 

are compatible with the suspicion of an incipient idiopathic erythropoietic 

disorder (e.g., panmyelopathy or smoldering leukosis or 

leukemia). 



a 

Small inclusions are usually a sign of nonspecific anomalies or 

artifacts 

d e 

f g 

Fig. 55 Erythrocyte inclusions. a Polychromatic erythrocyte with fine, dense basophilic 

stippling. b Erythrocyte with Howell–Jolly bodies (arrow) in addition to a 

lymphocyte (after splenectomy). c Erythrocyte with two Howell–Jolly bodies (arrow) 

alongside an orthochromatic erythroblast with basophilic stippling (thalassemia, 

in this case with functional asplenia). d Erythrocyte with a delicate Cabot 

ring (arrow) (here in a case of osteomyelosclerosis). e Thrombocyte layered onto 

an erythrocyte (arrow). f and g Fixation and staining artifacts. 



157 

b 

c

158 


Hematological Diagnosis of Malaria 

Various parasites may be found in the blood stream, e.g., trypanosomes 

and filariae. Among the parasitic diseases, probably only malaria is of 

practical diagnostic relevance in the northern hemisphere, while at the 

same time malarial involvement of erythrocytes may confuse the interpretation 

of erythrocyte morphology. For these reasons, a knowledge of 

the principal different morphological forms of malarial plasmodia is 

advisable. 

Recurrent fever and influenza-like symptoms after a stay in tropical regions 

suggest malaria. The diagnosis may be confirmed from normal 

blood smears or thick smears; in the latter the erythrocytes have been 

hemolyzed and the pathogens exposed. Depending on the stage in the life 

cycle of the plasmodia, a variety of morphologically completely different 

forms may be found in the erythrocytes, sometimes even next to each 

other. The different types of pathogens show subtle specific differences 

that, once the referring physician suspects malaria, are best left to the 

specialist in tropical medicine, who will determine which of the following 

is the causative organism: Plasmodium vivax (tertian malaria), Plasmodium 

falciparum (falciparum or malignant tertian malaria) and Plasmodium 

malariae (quartan malaria) (Table 27, Fig. 56). Most cases of 

malaria are caused by P. vivax (42%) and P. falciparum (43%). 

The key morphological characteristics in all forms of malaria can be 

summarized as the following basic forms: The first developmental stage of 

the pathogen, generally found in quite large erythrocytes, appears as small 

ring-shaped bodies with a central vacuole, called trophozoites (or the 

signet-ring stage) (Fig. 57). The point-like center is usually most noticeable, 

as it is reminiscent of a Howell–Jolly body, and only a very careful 

search for the delicate ring form will supply the diagnosis. Occasionally, 

there are several signet-ring entities in one erythrocyte. All invaded cells 

may show reddish stippling, known as malarial stippling or Schüffner’s 

dots. The pathogens keep dividing, progressively filling the vacuoles, and 

then develop into schizonts (Fig. 56), which soon fill the entire erythrocyte 

with an average of 10–15 nuclei. Some schizonts have brown-black pigment 

inclusions. Finally the schizonts disintegrate, the erythrocyte ruptures, 

and the host runs a fever. The separate parts (merozoites) then start a 

new invasion of erythrocytes. 

In parallel with asexual reproduction, merozoites develop into gamonts, 

which always remain mononuclear and can completely fill the 

erythrocyte with their stippled cell bodies. The large, dark blue-stained 

forms (macrogametes) are female cells (Fig. 57 d), the smaller, light bluestained 

forms (microgametes) are male cells. Macrogametes usually predominate. 

They continue their development in the stomach of the infected 

Anopheles mosquito. 



Young 

trophozoite 

Intermediate 

trophozoite 

Mature 

schizont 

Mature 

macrogametocyte 

Mature 

microgametocyte 

Plasmodium 

falciparum 

Plasmodium 

vivax 

Plasmodium 

ovale 

Plasmodium 

malariae 

Fig. 56 Differential diagnosis of malaria plasmodia in a blood smear (from Kayser, 

F., et al., Medizinische Mikrobiologie (Medical Microbiology), Thieme, Stuttgart, 

1993). 

159 



160 

Table 27 Parasitology of malaria and clinical characteristics (from Diesfeld, H., G. 

Krause: Praktische Tropenmedizin und Reisemedizin. Thieme, Stuttgart 1997) 

Disease Pathogen Exoerythrocytic 

phase 

incubation 

Falciparum 

malaria 

Tertian 

malaria 

Quartan 

malaria 


The example shown here is of the erythrocytic phases of P. vivax, because 

tertian malaria is the most common form of malaria and best shows 

the basic morphological characteristics of a plasmodia infection. 

Plasmodium 

falciparum 

P. vivax 

P. ovale 

⎫ 

⎪ 

⎬ 

⎪ 

⎭ 

7–15 days, does 

not form liver 

hypnozoites 

12-18 days, 

forms liver 

hypnozoites 

P. malariae 18-40 days, 

does not form 

liver hypnozoites 

Erythrocytic 

phase 

48 hours, 

recurring 

fever is rare 

48 hours 

Clinical characteristics 

Potentially lethal 

disease, widely 

therapy-resistant, 

there is usually no 

recurrence after 

recovery 

Benign form recurrences 

up to 2 years 

after infection 

Benign form recurrences 

up to 5 years 

after infection 

72 hours Benign form recurrences 

possible up 

to 30 years after 

infection 



a 

Conspicuous erythrocyte inclusions suggest malaria 

b c 

d e 

Fig. 57 Blood analysis in malaria. a Trophozoites in Plasmodium falciparum (falciparum 

or malignant tertian malaria) infection. Simple signet-ring form (1), double-invaded 

erythrocyte with basophilic stippling (2). Erythrocyte with basophilic 

stippling without plasmodium (3) and segmented neutrophilic granulocyte with 

toxic granulation (4). b and c Plasmodium falciparum: single invasion with delicate 

trophozoites (1), multiple invasion (2). d and e In the gametocyte stage of falciform 

malaria, the pathogens appear to reside outside the erythrocyte, but remnants 

of the erythrocyte membrane may be seen (arrow, e). For a systematic overview 

of malarial inclusions, see p. 159. 



161

162 


Polycythemia Vera (Erythremic 

Polycythemia) and Erythrocytosis 

Increases in erythrocytes, hemoglobin, and hematocrit above the normal 

range due to causes unrelated to hematopoiesis (i.e., the majority of cases) 

are referred to as secondary erythrocytosis or secondary polycythemia. 

However, it should be remembered that the “normal” range of values is 

quite wide, especially for men, in whom the normal range can be as much 

as 55% of the hematocrit! 

Table 28 Causes of secondary erythrocytosis 

Reduced O2 transport capacity – Carboxyhemoglobin formation in chronic 

smokers 

– High altitude hypoxia, COPD 

– Heart defect (right–left shunt) 

– Hypoventilation (e.g., obesity hypoventilation) 

Reduced O2 release from hemoglobin 

Renal hypoxia 

Autonomous erythropoietin biosynthesis – Renal carcinoma 

– Adenoma 

COPD = Chronic obstructive pulmonary disease 

– Congenital 2,3-diphosphoglycerate deficiency 

– Hydronephrosis, renal cyst 

– Renal artery stenosis 

An autonomous increase in erythropoiesis, i.e., polycythemia vera, represents 

a very different situation. Polycythemia vera—which one might 

call a “primary erythrocytosis“—is a malignant stem cell abnormality of 

unknown origin and is a myeloproliferative syndrome (p. 112). Leukocyte 

counts (with increased basophils) and thrombocyte counts often rise 

simultaneously, and a transition to osteomyelosclerosis often occurs in 

the later stages. 

Revised Criteria for the Diagnosis of Polycythemia Vera (according to 

Pearson and Messinezy, 1996) 

— A1 elevated erythrocyte numbers 

— A2 absence of any trigger of secondary polycythemia 

— A3 palpable splenomegaly 

— A4 clonality test, e.g., PRV-1 marker (polycythemia rubra vera 1) 

— B1 thrombocytosis ( 400 10 9 /l) 

— B2 leukocytosis ( 10 10 9 /l) 

— B3 splenomegaly (sonogram) 

— B4 endogenous erythrocytic colonies 

Diagnosis in the presence of: A1 + A2 + A3/A4 or A1 + A2 + 2 B 

Bone marrow cytology shows increased erythropoiesis in both polycythemia 

vera and secondary polycythemia. Polycythemia vera is the 

more likely diagnosis when megakaryocytes, granulopoiesis, basophils, 

and eosinophils are also increased. 



a 

c 

d 

Bone marrow analysis contributes to the differential diagnosis 

between secondary erythrocytosis and polycythemia vera 

Fig. 58 Polycythemia vera and secondary erythrocytosis. a In reactive secondary 

erythrocytosis there is usually only an increase in erythropoiesis. b In polycythemia 

vera megakaryopoiesis (and often granulopoiesis) are also increased. c Bone 

marrow smear at low magnification in polycythemia vera, with a hyperlobulated 

megakaryocyte (arrow). d Bone marrow smear at low magnification in polycythemia 

vera, showing increased cell density and proliferation of megakaryocytes. e In 

polycythemia vera, iron staining shows no iron storage particles. 



163 

b 

e

164 


Thrombocyte Abnormalities 

EDTA in blood collection tubes (e.g., lavender top tubes) can lead to 

aggregation (pseudothrombocytopenia). A control using citrate as anticoagulant 

is required. 

The clinical sign of spontaneous bleeding in small areas of the skin and 

mucous membranes (petechial bleeding), which on injury diffuses out to 

form medium-sized subcutaneous ecchymoses, is grounds for suspicion 

of thrombocyte (or vascular) anomalies. 

Thrombocytopenia 

Thrombocytopenias Due to Increased Demand (High Turnover) 

A characteristic sign of this pathology can be that among the few thrombocytes 

seen in the blood smear, there is an increased presence of larger, 

i.e., less mature cell forms. 

The bone marrow in these thrombocytopenias shows raised (or at least 

normal) megakaryocyte counts. Here too, there may be an increased presence 

of less mature forms with one or two nuclei (Figs. 60, 61). 

Drug-induced immunothrombocytopenia As in drug-induced agranulocytosis, 

the process starts with an antibody response to a drug, or its metabolites, 

and binding of the antibody complex to thrombocytes. Rapid 

thrombocyte degradation by macrophages follows (Table 29). The most 

common triggers are analgesic/anti-inflammatory drugs and antibiotics. 



Thrombocytes: increases, reductions, and anomalies may be 

seen 

b 

Fig. 59 Forms of thrombocytopenia. a This blood smear shows normal size and 

density of thrombocytes. b In this blood smear thrombocyte density is lower and 

size has increased, a feature typical of immunothrombocytopenia. continued 



165 

a

166 


Table 29 Most common triggers of drug-induced immunothrombocytopenia 

Analgesics 

Antibiotics 

Anticonvulsive drugs 

Arsenic, e. g., in water 

Quinidine 

Quinine 

Digitalis preparations 

Furosemide 

Gold salts 

Heparin! 

Isoniazid 

Methyldopa 

Spironolactone 

Tolbutamide 

“Idiopathic” immunothrombocytopenia. The name is largely historical, 

because often a trigger is found. 

➤ Postinfectious = acute form, usually occurs in children after rubella, 

mumps, or measles. 

➤ Essential thrombocytopenia, thrombocytopenic purpura (Werlhof disease) 

Thrombocyte antibodies develop without an identifiable trigger. This is 

thus a primary autoimmune disease specifically targeting thrombocytes. 

Secondary immunothrombocytopenias, e.g., in lupus erythematosus and 

other forms of immune vasculitis, lymphomas, and tuberculosis. 

Post-transfusion purpura occurs mostly in women about one week after a 

blood transfusion, often after earlier transfusions or pregnancy. 

Thrombocytopenia in microangiopathy. This group includes thrombotic– 

thrombocytopenic purpura (see p. 144) and disseminated intravascular 

coagulation. 

Thrombocytopenia in hypersplenism of whatever etiology. 

Fig. 59 Continued. c Pseudothrombocytopenia. The thrombocytes are not lying 

free and scattered around, but agglutinated together, leading to a reading of 

thrombocytopenia from the automated blood analyzer. d Giant thrombocyte (as 

large as an erythrocyte) in thrombocytopenia. Döhle-type bluish inclusion (arrow) 

in the normally granulated segmented neutrophilic granulocyte: May-Hegglin 

anomaly. 



Thrombocytes: increases, reductions, and anomalies may be 

seen 

c d 

Fig. 59 e Large thrombocyte (1) in thrombocytopenia. Thrombocyte-like fragments 

from destroyed granulocytes (cytoplasmic fragments) (2), which have the 

same structure and staining characteristics as the cytoplasm of band granulocytes 

(3). Clinical status of sepsis with disseminated intravascular coagulation. In automated 

counters cytoplasmic fragments are included in the thrombocyte fraction. 



167 

e

168 

Thrombocytopenias Due to Reduced Cell Production 

In this condition, blood contains few, usually small, pyknotic (“old”) 

thrombocytes. Only a very few megakaryocytes are found in the bone 

marrow, and these have a normal appearance. 

Causes 


Chronic alcoholism. There may be some overlap with increased turnover 

and folic acid deficiency. 

Chemical and radiological noxae. Cytostatics naturally lead directly to a 

dose-dependent reduction in megakaryocyte counts. A large therapeutic 

radiation burden in the area of blood-producing bone marrow has the 

same result, which may persist for many months. 

Virus infections. Measles, mononucleosis (Epstein–Barr virus, cytomegalovirus), 

rubella, and influenza may (usually in children) trigger thrombocytopenias 

of various types. In these cases, the virus affects the megakaryocytes 

directly. However, antibodies to thrombocytes may also arise 

in the course of these infections (p. 166), so that the pathomechanism of 

the parainfectious thrombocytopenias described by Werlhof in children 

may lie in impaired production and/or increased degradation of thrombocytes. 

Neoplastic and aplastic bone marrow diseases. All neoplasms of the bone 

marrow cell series (e.g., leukemia, lymphoma, and plasmacytoma), together 

with their precursor forms (e.g., myelodysplasia), lead to progressive 

thrombocytopenia, as do panmyelophthisis and bone marrow infiltration 

by metastases from solid tumors. 

Vitamin deficiency. Folic acid and vitamin B12 deficiencies from various 

causes (p. 152) also affect the rapidly proliferating megakaryocytes. In 

these cases, thrombocytopenia is often present before anemia and 

leukocytopenia in circulating blood, while the bone marrow shows 

copious megakaryocytes that have been blocked from maturation. 

Constitutional diseases. An amegakaryocytic thrombocytopenia without 

any of the above causes is rare. It is seen in children with congenital radial 

aplasia; in adults it tends usually to be an early sign of leukemia, 

myelodysplastic syndrome, or aplastic anemia. 

Wiscott-Aldrich syndrome (thrombocytopenia, immune deficiency, and 

eczema) is an X-chromosomal recessive disease in boys and presents with 

thrombocytopenia with ineffective megakaryopoiesis. 

The May-Hegglin anomaly (dominant hereditary transmission) is 

characterized by thrombocytopenia with giant thrombocytes and 

granulocyte inclusions, which resemble Döhle bodies (endoplasmatic reticulum 

aggregates). 



a 

c 

Variant forms of thrombocyte and megakaryocyte morphology 

in the bone marrow are diagnostic aids in thrombocytopenia 

e 

f 

Fig. 60 Morphology of thrombocytes and megakaryocytes. a Bone marrow in 

thrombocytopenia due to increased turnover (e.g., immunothrombocytopenia). 

Mononuclear “young” megakaryocytes clearly budding a thrombocyte (irregular, 

cloudy cytoplasm structure). b In thrombocytopenia against a background of 

myelodysplasia, the bone marrow shows various megakaryocyte anomalies: here, 

too small a nucleus surrounded by too wide cytoplasm. c–f In myelodysplasia 

(c and d) and acute myeloid leukemia (e and f), bizarre anomalous thrombocyte 

shapes (arrows) may occasionally be found. 

169 



b 

d

170 


Thrombocytosis (Including 

Essential Thrombocythemia) 

Reactive. Thrombocytosis in the form of a constant elevation of thrombocyte 

counts above an upper normal range of 300 000–450 000/µl, may be 

reactive, i.e., may appear in response to various tumors (particularly 

bronchial carcinoma), chronic inflammation (particularly ulcerative colitis, 

primary chronic polyarthritis), bleeding, or iron deficiency. The 

pathology of this form is not known. 

Essential Thrombocythemia 

Essential thrombocythemia, by contrast, is a myeloproliferative disease 

(see p. 114) in which the main feature of increased thrombocytes is accompanied 

by other signs of this group of diseases that may vary in severity, 

such as leukocytosis and an enlarged spleen. Severe thrombocythemia 

may also be seen in osteomyelosclerosis, polycythemia vera, and chronic 

myeloid leukemia, and for this reason the following specific diagnostic criteria 

have been suggested: 

Diagnostic criteria for essential thrombocytopenia (according to 

Murphy et al.) 

➤ Thrombocytes 600 10 9 /l (with control) 

➤ Normal erythrocyte mass or Hb 18.5 g/dl , 16.5 g/dl 

➤ No significant bone marrow fibrosis 

➤ No splenomegaly 

➤ No leukoerythroblastic CBC 

➤ Absence of morphological or cytogenetic criteria of myelodysplasia 

➤ Secondary thrombocytosis (iron deficiency, inflammation, neoplasia, 

trauma, etc.) excluded 

Large thrombocytes are found in the peripheral blood smear. However, 

these also occur in polycythemia vera and osteomyelosclerosis. 

Bone marrow cytology will show markedly elevated megakaryocyte 

counts, with the cells often forming clusters and often with hypersegmented 

nuclei. 

Fig. 61 Essential thrombocythemia. a Increased thrombocyte density and marked 

anisocytosis in essential thrombocythemia. b Large thrombocytes (1) and a 

micro(mega)karyocyte nucleus (2) in essential thrombocythemia. Micro(mega)karyocytes 

are characterized by a small, very dense and often lobed nucleus 

with narrow, uneven cytoplasm, the processes of which correspond to thrombocytes 

(arrow). 



a 

c 

Thrombocyte proliferation with large megakaryocytes: essential 

thrombocythemia, a chronic myeloproliferative disease 

Fig. 61 c and d Bone marrow cytology in essential thrombocythemia: there is a 

striking abundance of very large, hyperlobulated megakaryocytes (c); such megakaryocytes 

may also be seen in polycythemia vera. d Size comparison with basophilic 

erythroblasts (arrow). The cloudy cytoplasm of the megakaryocyte is typical 

of effective thrombocyte production. 



171 

b 

d

172 



Cytology of Organ Biopsies 

and Exudates* 

* Special thanks to Dr. T. Binder, Wuppertal, 

for the generous gift of several preparations. 



174 

Cytology of Organ Biopsies and Exudates 

In this guide to morphology, only a basic indication can be given of the 

materials that may be drawn upon for a cytological diagnosis and what 

basic kinds of information cytology is able to give. 

For specialized cytological organ diagnostics, the reader should refer to 

a suitable cytology atlas. Often appropriately prepared samples are often 

sent away to a hematological–cytological or a pathoanatomic laboratory 

for analysis. Thus, the images in this chapter are intended particularly to 

help the clinician understand the interpretation of samples that he or she 

has not investigated in person. 

In principle, all parenchymatous organs can be accessed for material for 

cytological analysis. Of particular importance are thyroid biopsy (especially 

in the region of scintigraphically “cold” nodules), liver and spleen 

biopsy (under laparascopic guidance) in the region of lumps lying close to 

the surface, and breast and prostate biopsy. Again, the cytological analysis 

is usually made by a specialist cytologist or pathologist. 

Lymph node cytology, effusion cytology (pleura, ascites), cerebrospinal 

fluid cytology, and bronchial lavage are usually the responsibility of the 

internist with a special interest in morphology and are closely related to 

hemato-oncology. 

Lymph Node Cytology 

The diagnosis of enlarged lymph nodes receives special attention here because 

lymph nodes are as important as bone marrow for hematopoiesis. 

While in most instances abnormalities in the bone marrow cell series can 

be detected from the peripheral blood, this is very rarely the case for lymphomas. 

For this reason, lymph node cytology, a relatively simple and 

well-tolerated technique (p. 24), is critically important for the guidance it 

can give about the cause of enlarged lymph nodes. Figure 62 offers a diagnostic 

flow chart. 



Anamnesis – sudden fast swelling 

slow onset, unclear 

symptoms: subfebrile, 

night sweat, weight 

loss 

Findings – pressure pain 

indolent often in one 

Blood 

analysis 

Serology/ – mononucleosis test 

immunology – toxoplasmosis 

– rubella 

– syphilis 

– tuberculin skin test 

or Search 

for disease 

focus 

– possible onset in youth 

– possible contact 

with animals 

– possible fever 

– focal, or distributed 

over several 

locations 

– relative lymphocytosis 

with 

stimulated forms 

– e.g. teeth 

– sinuses 

– infections of 

the genitalia 

– if findings are 

negative or unsuccessful 

therapy 

after 1 week 

considered reactive if 

the lymph node swelling 

does not recede after 

2 weeks or the cause 

is found 

D 

D 

D 

attempt to clarify 

the diagnosis after histology 

Lymph node 

biopsy 


possibly 

location, possibly 

localization of 

primary tumor 

175 

specific cell presentation 

(e.g. CLL, immunocytoma, 

ALL and others) 

or unspecific signs 

suspicion of tumor or 

malignant lymphoma 

D 

diagnosis based 

on histology 

Fig. 62 Diagnostic flow chart for cases of lymph node enlargement. (D) Diagnosis. 



176 


Reactive Lymph Node Hyperplasia and 

Lymphogranulomatosis (Hodgkin Disease) 

Reactive lymph node hyperplasia of whatever etiology is characterized by a 

confused mixture of small, middle-sized, and large lymphocytes. When 

the latter have a nuclear diameter at least three times the size of the predominating 

small lymphocytes and have a fair width of basophilic cytoplasm, 

they are called immunoblasts (lymphoblasts). Cells with deeply 

basophilic, eccentric cytoplasm and dense nuclei are called plasmablasts, 

and cells with a narrow cytoplasmic seam are centroblasts. Lymphocytes 

can also to varying degrees show a tendency to appear as plasma cells, e.g., 

as plasmacytoid lymphocytes with a relatively wide seam of cytoplasm. 

Monocytes and phagocytic macrophages are also seen (Fig. 63). 

Table 30 (p. 178) summarizes the different forms of reactive lymphadenitis. 

The basic cytological findings in all of them is always a complete 

mixture of small to very large lymphocytes. Occasionally more specific 

findings may indicate the possibility of mononucleosis (increased immature 

monocytes) or toxoplasmosis (plasmablasts, phagocytic macrophages, 

and possibly epithelioid cells). 

Any enlargement of the lymph nodes that persists for more than two 

weeks should be subjected to histological analysis unless the history, clinical 

findings, serology, or CBC offer an explanation. 

At first sight, the confusion visible in the cytological findings of lymphogranulomatosis 

(Hodgkin disease) is reminiscent of the picture in reactive 

hyperplasia (something which may be important for an understanding of 

the pathology of this disease compared with other malignant neoplasms). 

However, some cells elements show signs of a strong immunological 

“over-reaction” in which large, immunoblast-like cells form with welldeveloped 

nucleoli (Hodgkin cells). Sporadically, some of these cells are 

found to be multinucleated (Reed–Sternberg giant cells); infiltrations of 

eosinophils and plasma cells may also be found. Findings of this type always 

require histological analysis, which can distinguish between four 

prognostically relevant histological subtypes. In addition to this, the very 

lack of a clear demarcation between Hodgkin disease and reactive conditions 

is reason enough to conduct a histological study of every lymph node 

that appears reactive if does not regress completely within two weeks. 

In cases of histologically verified Hodgkin disease, cytological analysis 

is especially useful in the assessment of new lymphomas after therapy. 



a 

Reactive lymph node hyperplasia and lymphogranulomatosis 

(Hodgkin disease): a polymorphous mixture of cells 

b c 

Fig. 63 Reactive lymph node hyperplasia and lymphogranulomatosis. a Lymph 

node cytology in severe reactive hyperplasia. Large blastic cells alongside small 

lymphocytes (if it fails to regress, histological analysis is required). b Hodgkin 

disease: a giant mononuclear cell with a large nucleolus (arrow) and wide cytoplasmic 

layer (Hodgkin cell), surrounded by small and medium-sized lymphocytes. 

c Hodgkin disease: giant binuclear cell (Reed–Sternberg giant cell). 



177

Table 30 Sequence of steps in the diagnosis of reactive lymphoma 

178 

Anamnesis Symptoms Tentative diagnosis Diagnostic studies Cytology Histology 

() Non-specific 

lymphadenitis 


focus, non-specific 

changes in CBC and 

ESR 

Localized, painful Perifocal lymphadenitis 

Rapid progression 

(fever) 


() Adenitis with 

histiocytosis 

Mononucleosis Pfeiffer cells in the 

blood analysis, EBV 

serology (1) 

Diffuse, painfult; 

angina, possibly 

spleen 

Rapid progression, 

fever, 

sore throat 

Rubella Plasma cells in the 

blood, 

rubella-AHT (2) 

Most children Nuchal lymph 

nodes, later 

exanthema 

Epithelioid cell 

lymphadenitis 

Diffuse Toxoplasmosis Serology (3) () With 

epithelioid cells and 

macrophages 

Ingestion of raw 

meat 

Contact with cats 

Complement fixation 

reaction (adenoviruses, 

less commonlycoxsackieviruses) 

(4) 

Common viruses, 

specific adenoviruses 

Local 

Neck area 

Pharyngitis 

( conjunctivitis) 

() Epithelioid 

cells, Langhans 

giant cells 

Tuberculosis Thorax, local primary 

infections, skin test, 

pathogen in biopsy 

aspirate, possibly PCR 

Inflamed lymph 

nodes, possibly 

fistulae 

Slow growth, 

general malaise 



Epithelioid cells Epithelioid cell 

fibrosis 

Thorax, tuberculin 

test usually negative, 

ACE 

Sarcoidosis (Boeck 

disease) 

Slow growth Hard; possibly skin 

infiltrations

() It may be possible 

to determine the 

pathogen from the 

biopsy 

Listeriosis Agglutination test, 

complement fixation 

reaction 

Tonsillitis, neck 

lymph nodes 

Contact with 

animals 

Fever, spleen Brucellosis In case of fever: 

pathogen in blood, 

serology 

Contact with 

animals 

Milk intake 

Perforating 

lymphadenitis 

Epithelioid cells, 

giant cells 

Leukocytosis, lymphocytosis,complement 

fixation reaction 

Local primary lesion Cat-scratch disease 

Open wound, 

possibly from a 

cat 

Agglutination test 

Local primary lesion Tularemia (rabbit 

fever) 

Contact with 

wildlife 

Therapeutic 

excision 

Actinomycosis Leukocytosis, left shift “Gland” tissue in 

the biopsy material 

Inflamed hard infiltrates, 

possibly 

fistulae 

Little sense of 

illness 


Collagen disease Antinuclear factor 

(PCP, LE) Felty syndrome, 

Still disease 

Branchial cyst Epithelial cells, 

macrophages, and 

granulocytes 

Joints, spleen, 

possibly kidney 

Symptomatic 

joints 

Therapeutic 

excision 

No symptoms Submandibular 

swelling, no irritation 



() = Optional step; = usually diagnostic step, if there is no arrow, the diagnosis can be made on the basis of preceding steps. (1) = Positive from day 5; 

(2) = 1–4 days after exanthema, may be as much as 1 month; (3) = from week 4; (4) = from day 10. 

179

180 


Sarcoidosis and Tuberculosis 

The material of cell biopsies taken from indolent, nonirritated enlarged 

lymph nodes in the neck or axilla that have developed with little in the 

way of clinical symptoms, or from subcutaneous infiltration in various regions, 

can be quite homogeneous. With their thin, very long, ovoid nucleus 

(four to five times the size of lymphocytes), delicate reticular chromatin 

structure, and extensive layer of cytoplasm that may occasionally 

appear confluent with that of other cells, they are reminiscent of the 

epithelial cells that line the body’s internal cavities and are therefore 

called epithelioid cells. They are known to be the tissue form of transformed 

monocytes, and are found in increased numbers in all chronic inflammatory 

processes—especially toxoplasmosis, autoimmune diseases, 

and foreign-body reactions—and also in the neighborhood and drainage 

areas of tumors. They exclusively dominate the cytological picture in a 

particular form of chronic “inflammation,” sarcoidosis (Boeck disease). A 

typical finding almost always encountered at the pulmonary hilus combined 

with a negative tuberculin test will all but confirm this diagnosis. 

The appearance of a few multinuclear cells (Langhans giant cells) may 

allow confusion with tuberculosis, but clinical findings and a tuberculin 

skin test will usually make the diagnosis clear. 

Rapidly developing, usually hard, pressure-sensitive neck lymph nodes, 

seemingly connected with each other with some fluctuant zones and external 

inflammatory redness, suggest the now rare scrofulous form of 

tuberculosis. A highly positive tuberculin skin test also suggests this diagnosis. 

If any remaining doubts cannot be dispelled clinically, a very-fineneedle 

lymph node biopsy may be performed, but only if the skin shows 

noninflammatory, pale discoloration. 

The harvested material can show the potency of the tissue-bound 

forms of cells in the monocyte/macrophage series. In addition to mononuclear 

epithelioid cells, there are giant cell conglomerates made up of 

polynuclear epithelioid cells in enormous syncytia with 10, 20, or more 

nuclei. These are called Langhans giant cells. In scrofuloderma (tuberculosis 

colliquativa), there are also lymphocytic and granulocytic cells in the 

process of degradation, which are absent in purely productive tuberculous 

lymphadenitis. 



Epithelioid cells dominate the lymph node biopsy: Boeck disease 

or tuberculosis 

Fig. 64 Boeck disease and tuberculosis. a Lymph node cytology in Boeck disease: 

a special form of reactive cell pattern with (often predominating) islands 

and trains of epithelioid cells (arrow), which have ovoid nuclei with delicate chromatin 

structure and a wide, smoke-gray layer of cytoplasm. b Lymph node cytology 

in tuberculous lymphadenitis: in addition to lymphocytes and a few epithelial 

cells (1), enormous syncytes of epithelioid cell nuclei within one cytoplasm (arrow) 

may be encountered: the Langhans giant cell. 



181 

a 

b

182 


Non-Hodgkin Lymphoma 

Since the CBC is the first step in any lymph node diagnosis, lymph node biopsy 

is unnecessary in many cases of non-Hodgkin lymphoma (p. 70), because 

the most common form of this group of diseases, chronic lymphadenosis, 

can always be diagnosed on the basis of the leukemic findings of the 

CBC. 

However, when enlarged lymph nodes are found in one or more regions 

without symptoms of reactive disease, and the blood analysis fails to show 

signs of leukemia, lymph node biopsy is indicated. 

The relatively monotonous lymph node cytology in non-Hodgkin lymphomas 

and tumor metastases mean that histological differentiation is 

required. 

In contrast to Hodgkin disease, with its conspicuous giant cell forms 

(p. 177), non-Hodgkin lymphomas display a monotonous picture without 

any signs of a reactive process (p. 70). Clinically, it is enough to distinguish 

between small cell forms (which have a relatively good prognosis) and 

large cell forms (which have a poorer prognosis) to begin with. For a more 

detailed classification, see page 70 f. 

Histological analysis may be omitted only when its final results would 

not be expected to add to the intermediate cytological findings in terms of 

consequences for treatment. 

Metastases of Solid Tumors in Lymph Nodes or 

Subcutaneous Tissue 

When hard nodules are found that are circumscribed in location, biopsy 

shows aggregates of polymorphous cells with mostly undifferentiated nuclei 

and a coarse reticular structure of the chromatin (perhaps with welldefined 

nucleoli or nuclear vacuoles), and the lymphatic cells cannot be 

classified, there is urgent suspicion of metastasis from a malignant solid 

tumor, i.e. from a carcinoma in a variety of possible locations or a soft 

tissue sarcoma. 

As a rule, the next step is the search for a possible primary tumor. If this is 

found, lymph node resection becomes unnecessary. 

If no primary tumor is found, lymph node histology is indicated. The histological 

findings can provide certain clues about the etiology and also helps 

in the difficult differential diagnosis versus blastic non-Hodgkin lymphoma. 



a 

c 

In cases of non-Hodgkin lymphoma and tumor metastases, a 

tentative diagnosis is possible on the basis of the lymph node 

cytology 

d 

e 

Fig. 65 Non-Hodgkin lymphoma and tumor metastases. a Lymph node cytology 

showing small cells with relatively wide cytoplasm (arrow 1) in addition to lymphocytes. 

There are scattered blasts with wide cytoplasm (arrow 2): lymphoplasmacytic 

immunocytoma. b Lymph node cytology showing exclusively large blastoid 

cells with a large central nucleolus (arrow). This usually indicates large-cell non- 

Hodgkin lymphoma (in this case immunoblastic). c–e Metastatic disease from: 

c uterine carcinoma, d small-cell bronchial carcinoma, and e leiomyosarcoma. 

183 



b

184 


Branchial Cysts and Bronchoalveolar 

Lavage 

Branchial Cysts 

A (usually unilateral) swollen neck nodule below the mandibular angle 

that feels firm to pressure, but is without external signs of inflammation, 

should suggest the presence of a branchial cyst. Surprisingly, aspiration 

usually produces a brownish-yellow liquid. In addition to partially cytolysed 

granulocytes and lymphocytes (cell detritus), a smear of this liquid, 

or the centrifuged precipitate, shows cells with small central nuclei and 

wide light cell centers which are identical to epithelial cells from the floor 

of the mouth. Biopsies from a soft swelling around the larynx show the 

same picture; in this case it is a retention cyst from another developmental 

remnant, the ductus thyroglossus. 

Cytology of the Respiratory System, 

Especially Bronchoalveolar Lavage 

Through the development of patient-friendly endoscopic techniques, diagnostic 

lavage (with 10–30 ml physiological saline solution) and its cytological 

workup are now in widespread use. This method is briefly mentioned 

here because of its broad interest for all medical professionals with 

an interest in morphology; the interested reader is referred to the 

specialist literature (e.g. Costabel, 1994) for further information. Table 31 

lists the most important indications for bronchoalveolar lavage. 

Table 31 Clinical indications for bronchoalveolar lavage (according to Costabel 

1994) 

Interstitial infiltrates Alveolar infiltrates Pulmonary infiltrates in 

patients with immune 

deficiency 

Sarcoidosis (Boeck disease) 

Exogenous allergic alveolitis 

Drug-induced alveolitis 

Idiopathic pulmonary fibrosis 

Collagen disease 

Histiocytosis X 

Pneumoconioses 

Lymphangiosis carcinomatosa 

Pneumonia 

Alveolar hemorrhage 

Alveolar proteinosis 

Eosinophilic pneumonia 

Obliterating bronchiolitis 

HIV Infection 

Treatment with cytostatic 

agents 

Radiation sickness 

Immunosuppressive therapy 

Organ transplant 



a 

b 

Accessible cysts (e.g., branchial cysts) should be aspirated. Bronchial 

lavage is a cytological new discipline 

c d 

Fig. 66 Cyst biopsy and bronchoalveolar lavage. a Cytology of a lateral neck cyst: 

no lymphatic tissue, but epithelial cells from the floor of the mouth. b Normal 

ciliated epithelial cells with typical cytoplasmic processes. c Tumor cell conglomeration 

in small-cell bronchial carcinoma: conglomeration is typical of tumor cells. 

d Bronchoalveolar lavage in purulent bronchitis: a macrophage with pigment 

inclusion (arrow) is surrounded by segmented neutrophilic granulocytes. 



185

186 


Cytology of Pleural Effusions and Ascites 

Pleural effusions always require cytological diagnostic procedures unless 

they are secondary to a known disease, such as cardiac insufficiency or 

pneumonia, and recede on treatment of the primary disease. 

Pleura aspirates can be classified as exudates or transudates (the latter 

usually caused by hydrodynamic stasis). The specific density (measured 

with a simple areometer) of transudates, which are protein-poor, is between 

1008 and 1015 g/l, while for exudates it is greater than 1018 g/l. 

Cytological preparation may be done by gentle centrifugation of the 

aspirate (10 minutes at 300–500 rpm), which should be as fresh as 

possible; the supernatant is decanted and the sediment suspended in the 

residual fluid, which will collect on the bottom of the centrifuge tube. 

Nowadays, however, this procedure has been replaced by cytocentrifugation. 

Effusions that are noticeably rich in eosinophilic granulocytes should 

raise the suspicion of Hodgkin disease, generalized reaction to the presence 

of a tumor, or an allergic or autoimmune disorder. Purely lymphatic 

effusions are particularly suggestive of tuberculosis. In addition, all transudates 

and exudates contain various numbers of endothelial cells (particularly 

high in cases of bacterial pleuritis) that have been sloughed off from 

the pleural lining. 

Any cell elements that do not fulfill the above criteria should be regarded 

as suspect for neoplastic transformation, especially if they occur in 

aggregates. Characteristics that in general terms support such a suspicion 

include extended size polymorphy, coarse chromatin structure, welldefined 

nucleoli, occasional polynucleated cells, nuclear and plasma 

vacuoles, and deep cytoplasmic basophilia. For practical reasons, special 

diagnostic procedures should always be initiated in these situations. 

What was said above in relation to the cell composition of pleural effusions 

also holds for ascites. Here too, the specific density may be determined 

and the Rivalta test to distinguish exudate from transudate carried 

out. Inflammatory exudates usually have a higher cell content; a strong 

predominance of lymphocytes may indicate tuberculosis. Like the pleura, 

the peritoneum is lined by phagocytotic endothelial cells which slough off 

into the ascitic fluid and, depending on the extent of the fluid, may produce 

a polymorphous overall picture analogous to that of the pleural endothelial 

cells. It is not always easy to distinguish between such endothelial 

cells and malignant tumor metastases. However, the latter usually 

occur not alone but in coherent cell aggregates (“floating 

metastases”), the various individual elements of which typically show a 

coarse chromatin structure, wide variation in size, well-defined nucleoli, 

and deeply basophilic cytoplasm. 



c 

Tumor cells can be identified in pleural and ascites smears 

a b 

Fig. 67 Pleural effusion and ascites. a Pleural cytology, nonspecific exudate: dormant 

mesothelial cell (or serosal cover cell) (1), phagocytic macrophage with vacuoles 

(2), and monocytes (3), in addition to segmented neutrophilic granulocytes 

(4). b Cell composition in a pleural aspirate (prepared using a cytocentrifuge): variable 

cells, whose similarity to cells in acute leukemia should be established by cytochemistry 

and marker analysis: lymphoblastic lymphoma. c Ascites with tumor 

cell conglomerate, surrounded with granulocytes and monocytes, in this case of 

ovarian carcinoma. d Ascites cytology with an island of tumor cells. This kind of 

conglomeration is typical of tumor cells. 



187 

d

188 

Cytology of Organ Biopsies and Exudate 

Cytology of Cerebrospinal Fluid 

The first step in all hemato-oncological and neurological diagnostic 

assessments of cerebrospinal fluid is the quantitative and qualitative 

analysis of the cell composition (Table 32). 

Table 32 Emergency diagnostics of the liquor (according to Felgenhauer in Thomas 1998) 

➤ Pandy’s reaction 

➤ Cell count (Fuchs-Rosenthal chamber) 

➤ Smear (or cytocentrifuge preparation) 

– to analyze the cell differentiation and 

– to search for bacteria and roughly determine their types and prevalence 

➤ Gram stain 

➤ An additional determination of bacterial antigens may be done 

Using advanced cell diagnostic methods, lymphocyte subpopulations 

can be identified by immunocytology and marker analysis and cytogenetic 

tests carried out on tumor cells. 

Prevalence of neutrophilic granulocytes with strong pleocytosis suggests 

bacterial meningitis; often the bacteria can be directly characterized. 

Prevalence of lymphatic cells with moderate pleocytosis suggests viral 

meningitis. (If clinical and serological findings leave doubts, the differential 

diagnosis must rule out lymphoma using immunocytological 

methods.) 

Strong eosinophilia suggests parasite infection (e.g., cysticercosis). 

A complete mixture of cells with granulocytes, lymphocytes, and monocytes 

in equal proportion is found in tuberculous meningitis. 

Variable blasts, usually with significant pleocytosis, predominate in 

leukemic or lymphomatous meningitis. 

Undefinable cells with large nuclei suggest tumor cells in general, e.g., 

meningeal involvement in breast cancer or bronchial carcinoma, etc. The 

cell types are determined on the basis of knowledge of the primary tumor 

and/or by marker analysis. Among primary brain tumors, the most likely 

cells to be found in cerebrospinal fluid are those from ependymoma, 

pinealoma, and medulloblastoma. 

Erythrophages and siderophages (siderophores) are monocytes/macrophages, 

which take up erythrocytes and iron-containing pigment during 

subarachnoid hemorrhage. 

The cytological analysis of the cerebrospinal fluid offers important clues 

to the character of meningeal inflammation, the presence of a malignancy, 

or hemorrhage. 



a 

c 

e 

Viral, bacterial, and malignant meningitis can be distinguished 

by means of cerebrospinal fluid cytology 

g 

h 

Fig. 68 Cerebrospinal fluid cytology. a Cerebrospinal fluid cytology in bacterial 

meningitis: granulocytes with phagocytosed diplococci (in this case, pneumococci, 

arrow). b Cerebrospinal fluid cytology in viral meningitis: variable lymphoid 

cells. c Cerebrospinal fluid cytology in non-Hodgkin lymphoma: here, mantle cell 

lymphoma. d Cerebrospinal fluid cytology after subarachnoid hemorrhage: macrophages 

with phagocytosed erythrocytes. e–h Cerebrospinal fluid cytology in 

meningeal involvement in malignancy: the origin of the cells cannot be deduced 

with certainty from the spinal fluid cytology alone: (e) breast cancer, (f) bronchial 

carcinoma, (g) medulloblastoma, and (h) acute leukemia. 

189 



b 

d 

f

190 

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1998 

Begemann, H., J. Rastetter: Klinische Hämatologie, 4. Aufl. Thieme, Stuttgart 1993 

Bessis, M.: Blood Smears Reinterpreted. Springer, Berlin 1977 

Binet, J.L., A. Auquier, G. Dighiero et al.: A new prognostic classification of chronic 

lymphocytic leukemia derived from a multivariate survival analysis. Cancer 

1981; 48(1): 198-206 

Brücher, H.: Knochenmarkzytologie. Thieme, Stuttgart 1986 

Classen, M., A. Dierkesmann, H. Heimpel et al.: Rationelle Diagnostik und Therapie 

in der inneren Medizin. Urben & Schwarzenberg, München 1996 

Costabel, M.: Atlas der bronchoalveolären Lavage. Thieme, Stuttgart 1994 

Costabel V., J. Guzman: Bronchoalveolar lavage in interstital lung disease. Curr 

Opin Pulm Med 2001; 7(5): 255-61 

Durie, B.G.M., S.E. Salmon: A clinical staging system for multiple myeloma. Correlation 

of measured myeloma cell mass with presenting clinical features, response 

to treatment, and survival. Cancer 1975; 36: 842-854 

Heckner, F., M. Freund: Praktikum der mikroskopischen Hämatologie. Urban & 

Schwarzenberg, München 1994 

Heimpel, H., D. Hoelzer, E. Kleihauer, H. P. Lohrmann: Hämatologie in der Praxis. 

Fischer, Stuttgart 1996 

Huber, H., H. Löffler, V. Faber: Methoden der diagnostischen Hämatologie. 

Springer, Berlin 1994 

Jaffe, E. S., N. L. Harris, H. Stein, J. W. Vardiman: World Health Organization Classification 

of Tumours. Pathology and Genetics of Tumours of Haematopoietic and 

Lymphoid Tissues. IARC Press, Lyon 2001 

Lennert, K., A. C. Feller: Non-Hodgkin-Lymphome. Springer, Berlin 1990 

Löffler, H., J. Rastetter: Atlas der klinischen Hämatologie. Springer, Berlin 1999 

Murphy, S.: Diagnostic criteria and prognosis in polycythemia vera and essential 

thombocythemia. Semin Hematol 1999; 36(1 Suppl 2): 9-13 

Ovell, S. R., G. Sterrett, M. N. Walters, D. Whitaker: Fine Needle Aspiration Cytology. 

Churchill Livingstone, Edinburgh London 1992 

Pearson, T.C., M Messinezy: The diagnostic criteria of polycythaemia rubra vera. 

Leuk Lymphoma 1996;22(Suppl 1): 87-93 

Pralle, H. B.: Checkliste Hämatologie, 2. Aufl. Thieme, Stuttgart 1991 

Schmoll, H. J., K. Höffken, K. Possinger: Kompendium internistische Onkologie, 

3. Bde., 3. Aufl. Springer, Berlin 1999 

Theml, H., W. Kaboth, H. Begemann: Blutkrankheiten. In Kühn, H. A., J. Schirmeister: 

Innere Medizin, 5. Aufl. Springer, Berlin 1989 

Theml, H., H. D. Schick: Praktische Differentialdiagnostik hämatologischer und 

onkologischer Krankheiten. Thieme, Stuttgart 1998 

Zucker-Franklin, D., M. F. Greaves, C. E. Grossi, A. M. Marmont: Atlas der Blutzellen, 

2. Aufl. Fischer, Stuttgart 1990 



Index 

A 

Actinomycosis 179 

Addison disease 66 

Agammaglobulinemia 48 

Agranulocytosis 48, 86 

acute 86 

allergic 8 

bone marrow analysis 54, 86, 87 

classification 86 

subacute 86 

Alcoholism, chronic 168 

Allergic processes 8, 44 

basophilia and 124 

eosinophilia and 124 

Anemia 80, 106–107 

aplastic 8, 48, 56, 131, 140, 148–150 



congenital dyserythropoietic (CDA) 

147, 148 

diagnosis 130–131 

Diamond–Blackfan 146 

dimorphic 152 

hemolytic 131, 140–145 

causes 142 

microangiopathic 144, 150 

with erythrocyte anomalies 

144–145 

hemorrhage and 131 

hyperchromic 128, 152–155 

causes 152 

hyper-regenerative 128 

hypochromic 128–139 

bone marrow analysis 134–137 

infectious/toxic 131, 134–135, 136 

iron-deficiency 128–133, 136 

sideroachrestic 137 

with hemolysis 138–139 

hypoplastic 140 

congenital 146 

hyporegenerative 128 

immunohemolytic 8 

macrocytic 152–153 

191 

megaloblastic 43, 54, 56, 131, 

152–154 

normochromic 128, 140–151 

bone marrow analysis 140 

hemolytic 140–145 

renal 146 

paraneoplastic 131 

pernicious 140, 154 

refractory 106 

in transformation 108 

with excess blasts (RAEB) 54, 106 

with ring sideroblasts 106 

renal 146 

secondary 131, 134, 135, 136 

sickle cell 142, 144, 145 

sideroachrestic 131, 137 

sideroblastic 137 

smoldering 54 

Anisocytosis 130, 134–135, 137–139, 

152–153, 170 

Anulocytes 132, 133 

Ascites 186–187 

Auer bodies 89, 96–99 

Autoantibodies 142 

Autoimmune processes 8, 180 

anemia and 134 

autoagglutination 142, 143 


Automated blood count 19–20 

Azurophilic granules 96, 100 

B 

B-lymphocytes 48, 49 

function 6 

see also Lymphocytes 

Band cells 4, 6, 38–39, 57, 153 

diagnostic implications 38, 112, 113 

normal ranges and mean values 12 

Basophilia 124–126 

Basophilic stippling 134, 135, 

137–139, 156–157 

Basophils 44–45, 125 



192 

Index 

Basophils, diagnostic implications 44 

elevated counts 124–126 

function 5, 6 

in chronic myeloid leukemia 118, 

120, 121 


Bicytopenia 106, 149 

Blast crisis 

in chronic myeloid leukemia 

120–121 

in osteomyelosclerosis 123 

Blood cell series 2–5, 53 

regulation and dysregulation 7–8 

see also Erythropoiesis; Granulocytopoiesis 

Blood counts 

automated blood counts 19–20 

complete blood count (CBC) 25 

differential diagnosis 62–65 

differential blood count (DBC) 

17–19, 25–26 

indications 27 

erythrocytes 10, 13, 25 

leukocytes 14, 16, 25 

reticulocytes 11, 13, 32 

thrombocytes 15, 25 

Blood sample collection 9 

Blood smear 17–19 

staining 18, 19 

Blood–bone marrow barrier, destruction 

of 30, 32, 34 

Boeck disease 178, 180, 181 

Bone marrow 52–59 

analysis 52–59 

agranulocytosis 54, 86, 87 

cell density 52 

chromic myeloid leukemia 

118–119, 120, 121 

essential thrombocythemia 

170–171 

hypochromic anemias 134–137 

indications for 26, 27 

myelodysplasias 108, 109 

normochromic anemias 140 

polycythemia vera 162–163 

red cell series/white cell series 

ratios 53, 136 

space-occupying processes 

150–151 

thrombocytopenia 164, 169 

aplasia 146–150 

pure red cell aplasia (PRCA) 

146–148 

biopsy 20–22, 27 

cytology 20, 52–55 

disturbances 8 

histology 20, 26 

hyperplasia 149 

infectious/toxic 134 

medullary stroma cells 58–59 

neoplasms 150, 168 

carcinosis 131, 150–151 

Bone metastases 150, 168 

Branchial cyst 179, 184, 185 

Bronchoalveolar lavage 184–185 


Brucellosis 66, 179 

Bruton disease 48 

Burkitt lymphoma 71 

Burr cell 135 

C 

Cabot ring 156, 157 

Carcinoma 188, 189 

bone marrow 131, 150–151 

metastatic disease 182, 183 

Cat-scratch disease 179 

Centroblasts 176 

Cerebrospinal fluid 188–189 

Charcot-Leyden crystals 44 

Chickenpox 66 

Chromatin structure 4 

Collagen disease 179 

Complete blood count (CBC) 25 


Cyclic Murchison syndrome 40 

Cyst 

branchial 179, 184, 185 

retention 184 

Cytomegalovirus (CMV) infection 66, 

67, 68, 168 

D 

Diagnostic workup 25–27 

Diamond–Blackfan anemia 146 

Differential blood count (DBC) 17–19, 

25–26 


DiGeorge disease 48 



Disseminated intravascular 

coagulopathy (DIC) 144, 167 

Döhle bodies 39–41 

Drumstick appendages 42, 43 

Ductus thyroglossus 184 

Dyserythropoiesis 102, 106, 109 

congenital dyserythropoietic anemia 

(CDA) 147, 148 

Dysgranulopoiesis 102, 106 

Dysmegakaryopoiesis 102, 106, 109 

E 

Elliptocytosis 142 

Eosinophilia 111, 124, 125 

cerebrospinal fluid 188 

Eosinophils 44–45, 125 

diagnostic implications 44, 56 

elevated counts 124, 125 

functions 5, 6 

in chronic myeloid leukemia 118 


Epstein–Barr virus (EBV) infection 66, 

68–69, 168 

Erythremia 54, 162–163 

Erythroblastopenia 146–148 

Erythroblastophthisis 146 

Erythroblastosis 8 

Erythroblasts 30–33, 57 

acute erythroleukemia 100 

basophilic 30, 32, 54, 57, 85 


orthochromatic 31, 32, 54, 57 

polychromatic 32–33, 35, 54, 57 

Erythrocytes 7, 33 

assessment 26 

basophilic stippling 134, 135, 

137–139, 156–157 

counts 10, 13, 25, 128 

function 7 

inclusions 156–161 

iron deficiency and 132–133 


parameters 10–11 

red cell distribution width (RDW) 

11 

ring-shaped 130, 132, 133 

tear-drop 115, 123 

see also Anemia 

Erythrocytosis 

primary 162 

193 

secondary 162, 163 

Erythroleukemia 30, 93, 100 

in normochromic anemia 140 

Erythrophages 188 

Erythropoiesis 3, 30–33, 55 

bone marrow analysis 54, 136 

iron staining 56, 57, 109 

dyserythropoiesis 102, 106, 109 

in hypochromic anemia 136, 138 

in normochromic anemia 140 

megaloblastic 54 

Erythropoietin 146 

Essential thrombocythemia (ET) 8, 26, 

56, 114, 170–171 

diagnosis 170 

F 

Faggot cells 99 

Felty syndrome 179 

Ferritin granules 56 

Fibroblastic reticular cells 58, 59 

Folic acid deficiency 7, 38, 54, 149 

in hemolytic anemia 140, 141 

in hyperchromic anemia 152–154 

thrombocytopenia and 168 

Fragmentocytes 142, 143 

Fragmentocytosis 144 

G 

Index 

Gaisböck syndrome 53 

Gaucher syndrome 118 

Granulocytes 3, 4, 12, 13 

degrading forms 42 


hypersegmented 153–154 

precursors 34–37 

see also Basophils; Eosinophils; 

Neutrophils 

Granulocytopenia 66, 86 

Granulocytopoiesis 3, 5, 34–39 


dysgranulopoiesis 102, 106 

in acute myelomonocytic leukemia 

98 

in hypochromic anemia 136 

Granulocytosis 110 

Gumprecht's nuclear shadow 74 



194 

H 

Heinz bodies 142, 156 

HELLP syndrome 144 

Hematocrit 10 

Hematopoiesis 

extramedullary 30, 32 

see also Erythropoiesis 

Hemoglobin 

assay 10, 128 

deficiency 132 

mean cell hemoglobin content 

(MCH) 10, 13, 128 

mean cellular hemoglobin concentration 

(MCHC) 10, 11, 13 


see also Anemia 

Hemoglobinopathies 144 

Hemolysis 32, 54, 138–139, 142–143 

Hemolytic uremic syndrome (HUS) 

144 

Hemophagocytosis 46 

HEMPAS antigen 148 

Hepatitis 66 

Histiocytes 118 

reticular 58 

sea-blue 118 

Hodgkin cells 176, 177 

Hodgkin disease 26, 70, 176, 177 

eosinophilia 124 

Howell–Jolly bodies 139, 156, 157 

Hypereosinophilia syndrome 124 

Hypergammaglobulinemia 82, 131 

differential diagnosis 82 

Hypersensitivity reactions 44 


Hyperthyroidism 66 

Hypogammaglobulinemia 74, 82 

I 

Index 

IgM paraprotein 78 

Immunoblasts 176 

Immunocytoma, lymphoplasmacytoid 

70–71, 74, 77–78, 183 

Immunothrombocytopenia 165 

drug-induced 164–166 

idiopathic 166 

secondary 166 

Infection 36, 40, 46, 48, 112–113 


basophilia and 124 



see also specific infections 

Infectious lymphocytosis 66 

Infectious mononucleosis 68–69 

Influenza 168 

Iron 

deficiency 7, 56, 128–133 

blood cell analysis 132 


normal ranges 132 

Iron staining 56, 57, 109 

Isoantibodies 142 

L 

Langhans giant cells 180, 181 

Leukemia 8, 34, 40, 90–91 

acute 90–105 

basophilic 126 


characteristics 96 

classifications 91–93, 94, 104 


eosinophilic 124 

erythroleukemia 30, 93, 100 

lymphocytic (ALL) 104–105 


mast cell 126 

megakaryoblastic 102 

megakaryocytic 93 

monoblastic 93, 100–101 

monocytic 46, 89, 93, 100 

myeloblastic 96 

myeloid (AML) 89, 92, 94–97 

hypoplastic 102, 103 

with dysplasia 102, 103 

myelomonocytic 92, 98, 99 

promyelocytic 92, 98, 99 

aleukemic 149 

B-prolymphocytic (B-PLL) 70, 74, 77 

chronic 

basophilic 126 

lymphocytic (CLL) 66, 70, 74–79, 

90 


staging 76, 78 

myeloid (CML) 26, 44, 56, 90, 

114–121 



last crisis 120–121 

bone marrow analysis 118–119, 

120, 121 

characteristics 116, 124 

diagnosis 54, 111, 116–119 

myelomonocytic (CMML) 89, 90, 

107, 108 

eosinophilic 124 

erythroleukemia 30 

hairy cell (HCL) 71, 80, 81 

variant (HCL-V) 80 

lymphoplasmacytic 71 

megalokaryocytes 50 

peroxidase-negative 91 

peroxidase-positive 91 

plasma cell 48, 78, 82 

pseudo-Pelger granulocytes 42 

T-prolymphocytic 74, 77 

Leukemic hiatus 91 

Leukocyte alkaline phosphatase 54 

Leukocytes 3–4 

counts 14, 16, 25, 90–91 


Leukocytopenia 80, 107 

Leukocytosis 63, 110 

smoker's 111 

Leukopenia 63 

Listeriosis 179 

Loeffler syndrome 124 

Lung aspirates 186–187 

Lymph node biopsy 23, 24, 174–183 

metastatic disease 182, 183 

non-Hodgkin lymphoma 182, 183 

reactive lymph node hyperplasia 

176–179 

sarcoidosis 180–181 

tuberculosis 180–181 

Lymphadenitis 

reactive 176, 178–179 

tuberculous 181 

Lymphadenoma 54, 149 

chronic 74 

marginal zone 78, 80 

Lymphatic cells 63, 66 


differentiation in non-Hodgkin 

lymphoma 72–73 

reactive lymphocytosis 66–67 


Lymphoblasts 32, 176 

acute lymphoblastic leukemia (ALL) 

104–105 

195 

Lymphocytes 3, 4, 33, 48–49 

bone marrow 56 

diagnostic implications 48, 56, 66 

functions 6 

in infectious mononucleosis 68–69 

large granulated (LGL) 69 


plasmacytoid 77, 176 

see also Lymphocytosis; Lymphoma 

Lymphocytopoiesis 3 

Lymphocytosis 66–69, 74, 76 

constitutional relative 66 

infectious 66 

reactive 66–67, 86–87 

Lymphogranulomatosis see Hodgkin 

disease 

Lymphoma 69, 77, 82, 174 

B-cell 70, 71 

Burkitt 71 

centroblastic 71 

centrocytic 71 

classification 70–72 

follicular 71, 78, 79 

large-cell 71, 74 

lymphoblastic 72 

lymphoplasmacytic 78 

malignant 26 

mantle cell 71, 78, 79, 189 

marginal zone 71 

monocytoid 71 

non-Hodgkin (NHL) 26, 70–73 

blastic 70 

cell surface markers 72–73 

lymph node biopsy 182, 183 

precursor 70 

reactive 176–179 


splenic lymphoma with villous 

lymphocytes (SLVL) 80, 81 

T-cell 72 

cutaneous (CTCL) 74, 77 

Lymphomatous toxoplasmosis 66 

M 

Index 

Macroblasts 30 

Macrocytes 130, 153 

Macrophages 5–6, 59 

iron-storage 57, 58, 136 

role in erythropoiesis 30, 32 

Malaria 19, 158–161 



196 

Index 

Malignant lymphogranulomatosis 70 

Malignant transformations 8 

Mastocytosis 125, 126 

May-Hegglin anomaly 41, 166, 168 

Mean cell hemoglobin content (MCH) 

10, 13, 128 

Mean cell volume (MCV) 10, 13 

Mean cellular hemoglobin concentration 

(MCHC) 10, 11, 13 

Measles 66, 166, 168 

Medulloblastoma 188, 189 

Megakaryocytes 50–51, 57 


in chronic myeloid leukemia 115, 

118 

in essential thrombocythemia 

170–171 

in hyperchromic anemia 154 

in iron deficiency 136 


Megaloblasts 154 

Megalocytes 130, 152, 153 

Meningitis 188, 189 

Merozoites 158 

Metabolite deficiencies 7 

Metamyelocytes 4, 31, 35–37, 57, 153 

diagnostic implications 36 

Metastases 

bone 150, 168 

lymph nodes 182, 183 

Microangiopathy 144 

thrombocytopenia in 166 

Microcytes 132, 133 

Micromegakaryocytes 118 

Micromyeloblasts 34 

Microspherocytosis 144, 145 

Monocytes 3, 41, 46–47 

acute monocytic leukemia 100 


functions 5–6 


Monocytopoiesis 3 

in acute myelomonocytic leukemia 

98 

Monocytosis 46, 88–89 

causes 88 

Mononucleosis 66, 68–69, 168, 176, 

178 

Multiple myeloma (MM) 82, 83, 85 

Mumps 166 

Myeloblasts 4, 31, 34–35 

acute erythroleukemia 100 

acute myeloblastic leukemia 96–97 


see also Blast crisis 

Myelocytes 4, 36–37, 57 


in hyperchromic anemia 154 

Myelodysplasia (MDS) 40, 42, 

106–109, 131, 149 


classification 106, 108 


Myelofibrosis (MF) 26 

Myeloma 

multiple (MM) 82, 83, 85 

plasma cell 71, 82, 84 

Myeloproliferative diseases 32, 44, 50, 

56, 149 

basophilia and 124–126 

chronic myeloproliferative disorders 

(CMPD) 114–115 

differential diagnosis 115 

see also specific diseases 

N 

Natural killer (NK) cells 48 

Neutropenia 86 

autoimmune 86 


congenital/familial 86 

secondary, in bone marrow disease 

86 

Neutrophilia 110 

causes 111, 112 

reactive left shift 112–113 

without left shift 110 

Neutrophils 12, 31, 38–41, 45 



segmented 38–41, 43 


normal ranges and mean values 

12 

see also Neutropenia; Neutrophilia 

Non-Hodgkin lymphoma (NHL) 26, 

70–73 

blastic 70 

cell surface markers 72–73 

lymph node biopsy 182, 183 

Normal values 15–17 

Normoblasts 32, 138, 150 



in hemolytic anemia 140 

orthochromatic 140 

Nuclear appendages 42, 43 

O 

Osteoblasts 58, 59 

Osteoclasts 58, 59 

Osteomyelosclerosis (OMS) 26, 111, 

114, 122–123 


Oversegmentation 38 

P 

Pancytopenia 80 

Panmyelopathy 56, 148–149 

causes 149 

Panmyelophthisis 8, 148–150, 168 

Parasite infections 44, 124, 188 

eosinophilia and 124, 188 

Pel–Ebstein fever 40 

Pelger anomaly 40 

Perls' Prussion blue reaction 56 

Pertussis 66 

Pfeiffer cells 68, 69 

Philadelphia chromosome 114, 115, 

116 

Plasma cells 48–49, 57, 77, 82–85 

counts 56 


Plasmablasts 176 

Plasmacytoma 56, 70, 71, 82–85, 149 

morphological variability 84 

staging 84 

Plasmodia 19, 158–161 

Pleural effusions 186–187 

Poikilocytosis 130, 134, 135, 137–139, 

152 

Polychromasia 135 

Polychromophilia 134, 137 

Polycythemia 8, 53, 56, 111, 131 

erythremic 162–163 

Polycythemia vera (PV) 114, 122, 

162–163 

diagnosis 162 

rubra 26 

Proerythroblasts 30–31, 54, 85 

Promyelocytes 4, 31, 34–35, 44, 57 

acute promyelocyte leukemia 98, 99 

197 


Pseudo Gaucher cells 118 

Pseudo-Pelger formation 40, 41, 107 


Pseudopolycythemia 53 

Pseudothrombocytopenia 15, 51, 164, 

166–167 

Q 

5q-syndrome 108 

R 

Rabbit fever 179 

Reactive lymph node hyperplasia 176, 

177 

Reactive lymphocytosis 66–67 

Red cell distribution width (RDW) 11 

Reed–Sternberg giant cells 176, 177 

Reference ranges 15–17 

Refractive anemia with excess blasts 

(RAEB) 54 

Renal insufficiency 146 

Reticular cells, fibroblastic 58, 59 

Reticulocytes 32 

counts 11, 13, 32, 128 

in hemolytic anemia 140–141 


Reticuloendothelial system (RES), iron 

pull 134, 136 

Richter syndrome 74, 77 

Rubella 66, 166, 168, 178 

Russell bodies 84, 85 

S 

Sarcoidosis 178, 180–181 

Scarlet fever 40 

Schistocytosis 144 

Schizocytes 142 

Schizonts 158 

Schüffner's dots 158 

Scrofuloderma 180 

Sepsis 40, 41, 113, 167 

Sézary syndrome 74, 77 

Sickle cells 142, 144, 145 

Sideroachresia 56, 137 

Sideroblasts 56, 137 

Index 



198 

Sideroblasts, ring 56, 106, 109, 137 

Siderophages 188 

Spherocytosis 142 

Splenic lymphoma with villous 

lymphocytes (SLVL) 80, 81 

Splenomegaly 80, 112, 114–116, 142 

in chronic myeloid leukemia 

114–115, 116 


Staff cells 4 

Staining 18, 19 

iron staining of erythropoietic cells 

56, 57, 109 

Stem cells 2–3 

Still disease 179 

Stomatocytes 144, 145 

Stomatocytosis 144 

Strongyloides stercoralis 124 

Subarachnoid hemorrhage 188, 189 

Substantia granulofilamentosa 156 

T 

Index 

T-lymphocytes 48 

function 6 


Target cells 130, 138, 139, 142 

Thalassemia 131, 138–139, 142 

major 138, 139 

minor 138, 139 

Thrombocytes 7, 33, 50–51, 165–169 

counts 15, 25 


function 7 


Thrombocythemia 

essential (ET) 8, 26, 56, 114, 

170–171 

diagnosis 170 

idiopathic 122 

Thrombocytopenia 8, 56, 80, 113, 

164–169 

due to increased demand 164–167 

due to reduced cell production 

168–169 

in chronic myeloid leukemia 121 

in hypersplenism 166 

in microangiopathy 166 

in myelodysplasia 107 

Thrombocytopenic purpura (TTP) 131, 

144, 166 

post-transfusion 166 

Thrombocytosis 170–171 

reactive 170 

Thrombopoiesis 3 

Tissue mast cells 125, 126 

Toxic effects 8 

anemia 134 

Toxic granulation 40–41, 113 


Toxoplasmosis 176, 178, 180 

lymphomatous 66 

Tricytopenia 102, 106, 149 

Trophozoites 158, 161 

Tuberculosis 178, 180–181 

Tularemia 179 

Tumors 


biopsy 23 

see also specific tumors 

U 

Urticaria pigmentosa 126 

V 

Vacuoles 40, 41 

Virocytes 66, 68, 69 

Vitamin B12 deficiency 7, 38, 54, 149 

in hyperchromic anemia 152–154 


W 

Waldenström syndrome 78 

Werlhof syndrome 56 

Wheel-spoke nuclei 84 

Whooping cough 66 

Wiscott-Aldrich syndrome 168 

X 

X-chromosome 42, 43 

Z 

Zieve syndrome 142

Color Atlas of Hematology (2004).pdf

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